The 180 Formula: Heart-rate monitoring for real aerobic training.

maf 180 formula

A heart-rate monitor is the most important tool for developing optimal endurance and better fat-burning. This simple device is a valuable tool that not only guides your training but is part of an important assessment process, and can even be used in some competitive situations. Unfortunately, most people use their heart-rate monitors only to see how high their heart rate gets during a workout, or evaluate resting heart rate in the morning.

In the 1970s, I first measured heart rates as a student in a biofeedback research project. Through this research, it became evident that using the heart rate to objectively measure body function was simple, accurate and useful, especially for athletes. I began using heart rate to evaluate all exercising patients, and by the early 1980s developed a formula that anyone could use with their heart monitor to help build an aerobic base.

This “180 Formula” enables athletes to find the ideal maximum aerobic heart rate in which to base all aerobic training. When exceeded, this number indicates a rapid transition towards anaerobic work.

A good aerobic base isn’t important only for endurance athletes. The system that controls the body’s stress response is functionally linked to the anaerobic system. In other words, if you depend too much on your anaerobic system, you’ll be more stressed, and therefore more likely to overtrain or become injured. I discuss these topics more in depth in The MAF Test and in The New Aerobic Revolution.

The 180 Formula

To find your maximum aerobic training heart rate, there are two important steps.

  1. Subtract your age from 180.
  2. Modify this number by selecting among the following categories the one that best matches your fitness and health profile:

a)  If you have or are recovering from a major illness (heart disease, any operation or hospital stay, etc.) or are on any regular medication, subtract an additional 10.

b)  If you are injured, have regressed in training or competition, get more than two colds or bouts of flu per year, have allergies or asthma, or if you have been inconsistent or are just getting back into training, subtract an additional 5.

c)  If you have been training consistently (at least four times weekly) for up to two years without any of the problems in (a) and (b), keep the number (180–age) the same.

d)  If you have been training for more than two years without any of the problems in (a) and (b), and have made progress in competition without injury, add 5.

For example, if you are 30 years old and fit into category (b), you get the following: 180–30=150. Then 150–5=145 beats per minute (bpm).

In this example, 145 must be the highest heart rate for all training. This allows you to most efficiently build an aerobic base. Training above this heart rate rapidly incorporates anaerobic function, exemplified by a shift to burning more sugar and less fat for fuel.

Initially, training at this relatively low rate may be difficult for some athletes. “I just can’t train that slowly!” is a common comment. But after a short time, you will feel better and your pace will quicken at that same heart rate. You will not be stuck training at that relatively slow pace for too long. Still, for many athletes it is difficult to change bad habits.

If it is difficult to decide which of two groups best fits you, choose the group or outcome that results in the lower heart rate. In athletes who are taking medication that may affect their heart rate, wear a pacemaker, or have special circumstances not discussed here, further consultation with a healthcare practitioner or specialist may be necessary, particularly one familiar with the 180 Formula.


  • The 180 Formula may need to be further individualized for people over the age of 65. For some of these athletes, up to 10 beats may have to be added for those in category (d) in the 180 Formula, and depending on individual levels of fitness and health. This does not mean 10 should automatically be added, but that an honest self-assessment is important.
  • For athletes 16 years of age and under, the formula is not applicable; rather, a heart rate of 165 may be best.

Once a maximum aerobic heart rate is found, a training range from this heart rate to 10 beats below could be used. For example, if an athlete’s maximum aerobic heart rate is determined to be 155, that person’s aerobic training zone would be 145 to 155 bpm. However, the more training closer to the maximum 155, the quicker an optimal aerobic base will be developed.

The story behind the 180 Formula

The heart rate is a direct reflection of the body’s oxygen need. The relationship between one heartbeat and the next is associated with heart rate variability, which reflects parasympathetic nervous system (PNS) function. This is an important factor that professionals can use to assess heart health, and for athletes to evaluate recovery from training and racing.

The heart has a built-in mechanism of nerves that controls its own rhythm (to maintain a heart rate of around 70 to 80 beats per minute), but the brain, through the action of the autonomic nervous system and various hormones, can compel the heart to produce a wide range of heart rates based on the body’s needs. This rate can be as low as 30 to 40 in those with great aerobic function to as high as 220 or higher in young athletes during all-out efforts.

In the late 70s and early 80s I had in my office several bulky heart monitors, which I used for heart-rate evaluation. Whether the athlete was on a treadmill, on a stationary bike in the clinic, on the track, or at another location, I would record a number of pre- and post-workout features.

Training at various intensities affects both posture and gait: the greater the anaerobic work, the more distorted the body’s mechanics become. These changes are due, in part, to previously existing muscle imbalance and muscle problems that develop during the workout. By correlating this mechanical efficiency with heart rate at various points before, during and after workouts, I found an ideal training heart rate—one which promoted optimal aerobic function without triggering significant anaerobic activity, excess stress, muscle imbalance or other problems.

The heart rate I found to be ideal in my assessment was often significantly lower from the results of the commonly-used 220 Formula. However, it was becoming evident that athletes who used the 220 Formula to calculate their daily training heart rate showed poor gait, increased muscle imbalance, and other problems following a workout. Often, these athletes were overtrained.

It soon became evident that athletes needed more consistent training quality. Each athlete needed to have his or her own heart monitor and train with it every day. With Polar’s entry into the marketplace in 1982 came the advent of modern heart monitors, which sensed the heart rate directly from the chest wall and transmitted the information to a wristwatch. Athletes who wore heart-rate monitors during each workout felt better and improved in performance at a faster rate than others who trained without a monitor.

My new goal was to find a way that any athlete could determine an optimal training heart rate, using some simple formula—ideally one that resulted in a very similar or identical heart rate as my manual assessments.

Over time, I began piecing together a mathematical formula, using as a guide the optimal heart rates in athletes who had previously been assessed. Instead of the 220 Formula—220 minus the chronological age multiplied by some percentage—I used 180 minus a person’s chronological age, which is then adjusted to reflect their physiological age as indicated by fitness and health factors.

By comparing the new 180 Formula with my relatively lengthy process of one-on-one evaluations, it became clear that this new formula worked very well. In other words, my tedious assessment of an individual athlete and the 180 Formula resulted in a number that was the same or very close in most cases.

In the early 1980s, I settled on the final, most effective formula, which is the one in use today: 180 minus a person’s chronological age, which is then adjusted to reflect their physiological age as indicated by fitness and health factors. The use of the number 180 is not significant other than as a means to finding the end heart rate. Plus, 180 minus age itself is not a meaningful number; for example, it is not associated with VO2max, lactate threshold, or other traditional measurements. The end number is an athlete’s maximum aerobic heart rate. Thanks to the 180 Formula, all athletes can now obtain their ideal individual aerobic training rates.


  • Brian G. Fay says:

    After reading Chris McDougall’s Natural Born Heroes and reviewing your site (which looked very different before today, nice update), I took myself out for a run with the HRM and the 180 rule. I have been running at what I call my all-day pace as I’m playing my way toward my first 50K. The running I have been doing has been great and I’ve felt like going longer and longer. I did the math 180 – 46 (my age) and set the HRM for a 124-134 zone thinking it would be great. Not so much. To get to 124 required a ton of effort. My body told me it was too hard but the formula and HRM told me the opposite.

    I remembered then my previous attempts with a HRM. I have a resting heart rate in the low forties even when I’m not in good shape and my HR drops ten within just a few moments of switching from running to walking. This is good, but it also means that I have consistently had to subtract about ten beats per minute from any calculation. I’ll go out today with the zone set for 114-124 and see how it _feels_. My guess is that the goal of your plan is for me to stay in a zone that feels lighter and allows me to go longer rather than pushing into a specific number that leaves me feeling wiped out and sore.

    If I get a chance, I’ll let you know how it goes. Thank you for the good stuff you’ve got going here on the site. Be well.

    • Brian:

      Thanks for your comment. I’m one of the moderators here on the site. I’m glad you’re using Dr. Maffetone’s 180-formula to figure out your heart rate. It’s interesting to me that the MAF heart rate was difficult to get to. Did you warm up for 10-15 minutes before trying to reach the heart rate?

      • Cary Stephens says:

        I am similar to Brian in that my Maf rate seems a bit high. I am an endurance runner (since childhood) who has competed in triathlon during the 80s and 90s and now does ultramarathon trail racing. I have a resting heart rate in the mid 30s when trained and a max heart rate rate of only 160. I am 46. I started using the Maff formula last year in an attempt to address chronic nausea while engaged in longer 3+ hour endurance sessions and found that the perceived effort was actually on the higher side of my all day pace. I had a Metabolic efficiency test done and found that my RER crossover point (50/50 fat and carb metabolism) was at 132 bpm. This was lower than my Maf rate of 135 (180 – age) and actually close to my 50k race pace. So, since I have the data, stated in terms RER, where does the Maf rate typically land? Does it approximate the crossover point where I am burning 50 percent fat or some lower rate with even higher fat burning? I settled on a training rate of 115-125 for several months, and combined with a switch to a high fat diet went from bonking in a 50k on 300 kcal/hour to finishing 30 minutes faster on 150 kcal/hour. My nausea after events has considerably improved and my performance/results have too. I think building the aerobic engine is the key. Thanks for any feedback you could give.

        • Cary:

          Getting an extensive analysis done on your body beats any formula. I would keep going with that, if it works for you.

        • Jeff Carter says:

          Hi Cary:

          Will you share what you’re eating and drinking during events? I’ve cut out sugars and grains, currently finishing up the “two week test”, and have backed off my training intensity slightly, to my 180 formula hr range. I’ve tried a number of products for training and racing, most recently settling on Ensure as my primary nutrition source, along with bites of potato, pb&j sandwiches, and sports bars to stave off the hunger pangs. I also drink water and take electrolyte capsules, adjusting the dose based on temperature and intensity.


        • Nick says:

          I seem to be similar to Brian & Cary and having just read about and started the Maf regime found comfortably staying in the proscribed heart rate range (180 – 54 = 126 to 116) on a static bike hard going.

          I live in Kenya and am currently at 2,000m (for the past 2-weeks) but normally live & train at around 1,700m averaging 8.5hrs bike & x-trainer per week so am fully acclimatized.

          Is there any factor in terms of the ideal heart rate bracket that I should apply because of the altitude?

          On the basis of my current admittedly limited experience, I intend to drop my bracket by 5bpm as I think this will do the trick….or am I cheating myself??

          Many thanks for any advice.

          • Nick:

            Good question. The answer to your first question is “no.”

            Your second question warrants a slightly longer answer:

            The most important thing is to be specific with our training. In other words, our training should be about answering this question: what are we trying to develop? If it is the aerobic base that we’re trying to develop, then being slightly conservative is what we want. In the words of some big running guru, “keep your slow runs slow and your fast runs fast.” 5 more beats per minute isn’t really going to give us significant aerobic development—most of my MAF runs are 5-6 BPM below my MAF HR—but it may put us just over the brink where our aerobic development slows down due to a mild anaerobic response.

            In other words, chasing a tiny bit more (imagined) aerobic development can make us cross a threshold where although we’re not going to hurt ourselves, the pursuit of our stated goal—developing our aerobic base—is a good bit less effective than before.

      • jpvisual says:

        Hi Ivan,

        I’m new to the 180 method and I’m going to subtract 5. I’m a cyclist that has not raced in about 3 years and just getting back to consistent workouts. I have no plans to race in the future, just looking to exercise for long term health and fitness.

        My question is:

        How long to I need to to train at the “-5” number before I can move up to the default of “180 – my age”?


        • Jpvisual:

          Thanks for your question. It’s a really good one. But we don’t really characterize 180-age as the “default.” In our opinion, the “default” should be 180-age +5 (because you’ve been progressing in training and racing). In other words, the default should be “super healthy and athletic.” Think of 180-age as a useful way to get to your MAF number, not as the “default” MAF number itself.

          The best way to know when you change it is when you can disingenuously tell yourself that you’re “back to” training, and have made a habit out of it. It’s hard to define, but we all know how it feels to have built a habit. My point is that once you’re “back” to training, it feels that way because the body has adapted to it. So, your best good-faith estimate is the best there is. How much time does this usually mean? 2 months on the safe side.

          • jpvisual says:

            Thanks for getting back to me Ivan.

            I have one more quick question. I totally know what you mean about that feeling of being “back to/in the habit” of training.

            So once I’m feeling like I’m in good shape and back to regular training (in 2-3 months) should I add 5, bringing me back to 180 – age, or go right to 180 – age +5? If I make the jump to the latter, I’ll actually be going up 10 (from 136 to 146). Is that too much of a jump at once, or should I progress from 136 to 141, then after another few months if everything is going well, go from 141 to 146?


          • Jpvisual:

            It’s really a judgment call. It’s better to be on the safe side and make the change slowly. What I should tell you is that it’s really important to “keep your slow runs slow and your fast runs fast,” meaning that you want to be very sure that adding those 5 BPM isn’t crossing the threshold over into anaerobic function and producing a slightly different (but significantly so) training stimulus than the one you want from your aerobic training. The key here is that being conservative by 5 BPM won’t really do anything to reduce the aerobic training stimulus, but adding 5 BPM may change the kind of training stimulus. So the key is to make sure you don’t change the kind of stimulus you want.

      • Deb H. says:

        Is there a breakdown calculation for training zones? I am 58 therefore my max bpm is 122. I use a Garmin for my monitor. Do I enter 122 as my max rate or 180 then further breakdown bpm into the different zones? If so how do I determine the different levels? Thanks, excited to give this a try.

      • Hila says:


        I live in an area with very high humidity percantage.. summer time 70-90% and winter is also relatively high up..
        should i make adjustments?
        thank you

      • Dave C says:

        Hello. I have the opposite problem. I am unconditioned right now- I havent done much cardio in 5 years. I get to my MAF rate (132 bpm) before I can even run. Even walking at 3.6 mph on a treadmill gets me there. Ultimately, my goal is to run 5Ks and 10Ks. What do you recommend?

        • Hello Dave,

          What will do it for you in the long term is to continue training at your MAF HR and get faster and faster. If you’re just starting, we recommend not doing any training or racing above the MAF HR until you’ve been at it for 2-3 months, in order to let the body get used to activity without putting a lot of stress on it. A good way to increase your training time is to start by doing 30 minutes 3X a week, and increase 5 minutes every 2 weeks so that you are doing 50 minutes by the end of 2 months. Ideally, this training time includes a warm-up and cool-down of 15 min each: at first you’ll be essentially only warming-up and cooling down, and then you’ll be running 5 minutes at MAF, then 10 minutes, then 15, then 20. The goal of this progression, as I’ll discuss more below, is not just to make you “faster,” but to keep you healthy in order to make your improvement more consistent and predictable, and prolong it into the future.

          To run any race up to a half marathon, its best if you know that you can run that distance in one workout (at an easy intensity) and be able to cover at least twice that distance every week without fatigue piling up. The same goes for a 10k. Once you can do this, you can go ahead and start participating in races of a 5k/10k length. It’s best to run them at a speed that you can maintain the entire race. (Your racing HR and race speed for these distances will always be higher/faster than your MAF HR). But here’s the catch:

          In order to be able to run those races substantially faster, more consistently, with less wear-and-tear, and a lower incidence of injury, you’ll have to continue training at your MAF HR and increasing your MAF speed. What you’ll find is that at the beginning, your maximum race speed is much faster than your MAF HR. (This divide means that you’re running the race that much more anaerobically, which will produce more wear-and-tear, increase your likelihood of injury, etc.)

          But as you train at MAF, your MAF speed will increase disproportionately to your race speed, meaning that you’ll most likely get faster at racing, but your MAF speed will also close in on your race speed. As this happens, you’ll begin to experience that racing is “easier,” that you recover more quickly, and that you can train more and better with less wear-and-tear. Once you enter into this virtuous cycle, you’ll find that you can start adding a bit more speed and strength into your training without substantially increasing your fatigue. This is when you’ll be able to start racing faster without the typical continued injury, allowing you to train more consistently and improve more predictably and continuously.

          Ultimately, that’s what MAF is all about — if you want to get fast, fast (without an eye to the future), there’s certainly “better” methods. But if you want to keep getting faster for longer, and making the process more enjoyable and less painful, MAF is certainly the way to go.

          Does this make sense? Let me know if I answered your question – I’m happy to go more specific if need be.

          • Darius Gear says:

            This Q & A is in my ball park. I use to do 6.5 min in and now I feel the same effort at 5.5 min per km. Sticking to MAF really works. It takes time to improve but that is a battle of patience not fitness.

      • Walter Shanley says:

        I just read the article above and have quite the opposite situation as Brian. I am 55 Y.O. and use an inhaler, so I figured 180-55-5= 120!
        My resting hr is in the 60-72 range but my primary exercise is bicycle riding in which my avg. HR on any given ride is about 150 with peaks up to 180…(there are a good amount of hills but nothing beyond 5%). If I tried to keep my hr down to 120 I wouldn’t be going anywhere! What do you say about this?

      • Mike says:

        Hi Ivan,
        When using the Maffetone Method how many of your weekly miles should be done at the 180 HR calculation?
        If my training program called for 30 miles this week. How many of those miles at the 180 formula?

    • katie says:

      Would insulin (for type 1, NOT type 2 diabetes) count as a ‘regular medication?’

      • Katie:

        Absolutely. In fact, any kind of diabetes counts as a “major illness,” particularly since the goal of the 180-formula is to figure out at what heart rate the body is working fully aerobically. Since diabetes is essentially all about the body’s mismanagement of energy (carbohydrates and fats) you want to be especially conservative with the score when it comes to diabetes (and any other illness related to metabolic syndrome).

        I hope this answers your question.

        • Mike says:


          Thank you for all of the helpful information. Do medicines like Fluoxetine (Prozac) count in determining your heart rate with the 180 formula?


          • Yes, absolutely. Prozac is a serotonin reuptake inhibitor. Serotonin fluctuations drive large-scale changes in the nervous system, as well as affecting the hypothalamus, which controls the stress response. (Long story short). This means that they alter your stress levels, your heart rate, and consequently the ratio of aerobic-to-anaerobic function. Whenever this is happening, you want to be conservative with the 180-Formula.

        • casey says:

          i dont know, i do a low carb diet (dr bernsteins) and am a type 1 diabetic. it isnt that my body can’t process carbohydrates, it is missing insulin. so im replacing the insulin that a person without diabetes already has in them. there isn’t resistance like with type 2. for me, 180-35, my goal is 145. which i can comfortably run at all day. (half marathoner). I guess, I could say I add 5 back to 135 for a goal of 140 because ive been running for over 2 years. but i have had injuries, from running in the wrong shoes. (and my chiropractor is actually the person that referred me here!)

          • Casey:

            I understand. But missing insulin is like missing a part of the engine. Without that insulin, that engine can’t do with carbs what it needs to. If you put insulin into the body to regulate blood sugar, those insulin levels aren’t being regulated by other hormones (such as leptin, a hormone which increases the usage of fats) whose co-functioning heavily influences the functioning of the aerobic system. So, for example, when leptin levels increase (to promote fat-burning), it’s supposed to naturally lower insulin by sending signals to the pancreas. In your case, those insulin levels wouldn’t lower in relation to leptin like they should.

            Furthermore, insulin suppresses leptin production. By suppressing it, you de facto reduces the effectiveness of the aerobic system. This means that unless you can perfectly match your insulin replacement to the type and level of activity that you’re doing, specifically taking into account the action that leptin (to name one hormone of many) should be doing, your aerobic system will still be functioning anomalously. And your body will be under more stress. For both of those reasons, the chance is very high that you’ll be promoting anaerobic function.

            It’s better to be conservative, in these situations. If you add those 10 beats per minute, all bets are off. And “all bets are off” doesn’t mean “you’re wrong.” It means “in your particular case, adding 10 BPM might (or might not) turn out just fine, for external reasons that we don’t know about and haven’t considered. But for another type 1 diabetic, it might be a problem.”

      • jpvisual says:

        Thanks Ivan,

        I’m actually a cyclist, but I know the same rules apply.

        To be on the safe side, how about I move up 5 bps at a time after showing improvement on my MAF tests over a 2-3 month period? Also, when I’m training in general, I should try to stay 5-6 BPS under my max hr, no matter what level I’m at.

        Does that sound like a good conservative plan to you?


        • Jpvisual:

          That sounds perfect. It leaves you with a good buffer zone.

        • david neilson says:


          I’m another T1D, in my case using an insulin pump and only quick acting insulin. What that allows me to do is to more closely mimic the bodies natural response to exercise, but not perfectly yet without a closed loop system.

          With an effective life of 4hours in the body for an artificial insulin, I can turn my pump down ahead of endurance exercise, knowing that I will then have no difficulties, and will not be supressing other mechanisms that you talk about nor ending up with major blood sugar crashes through activation of things like the GLU4 receptors.

          If I read a lot of the texts on managing T1 and exercise, they talk about 100g/hr of carbs whereas with my actions above I’m closer to 20g/hr carbs while exercising. I’ve also adopted a low carb diet which reduces the circulating insulin in general and promotes more stable blood sugar and over time reduces the risk or diabetic complications.

          with all that, I don’t feel a need to reduce my MAF target at all on the basis of a major illness. In my view I had a major illness 4 years ago when a dose of flu triggered an auto-immune condition, not now.

          • Hi David,

            I can’t really suggest modifications to the 180-formula based on what you’ve told me as there is a lot more that I would need to know. That said, the formula is meant to provide a ballpark estimate of where your MAF HR resides, so if you feel that your MAF HR may be higher, it’s good to give it a try.

    • Bruce Mitchell says:

      A friend put me onto Dr Phil Maffetones training techniques a couple of days ago and I have been reading as much as I can ever since. I have ordered his book and are going out to buy a HRM watch.
      I will be 57 in a couple of weeks and are a type 1 diabetic with good control. I have been undertaking swim and run training spasmodically over the last 30 years to help with diabetic controls. I run in winter up to 8km at a slow pace of 6.30 per Km, and swim in summer enough to compete in ocean swims upto 2 km.
      My questions are what should my heart rate equation be and what herat rate monitor should I purchase now that there are watches with built in HRM as opposed to chest straps. I would like to use it for swimming and running if possible.

      • Bruce:

        I recommend this link. Use the guidelines on the article to figure out your MAF heart rate, and be conservative: if it says to subtract BPM due to an injury, do so for any injury. If it says to subtract BPM for regular medication, do so for any regular medication.

    • Arnie Cerny says:

      I am 56 (almost 57). I have not had any injury for over 3-4 years. So my MAF number is 129. I am 5 days into running with the MAF method. I am running at 10:30-11:15 minutes per mile. My heart rate is typically 134-136 on flat trails. It will go to 140-144 when I run hills along some trails. I am going as slow as I can. I am wondering if this will affect my ability to reach MAF!!! I decided to go to MAF because I noticed that I was running so hard that I had to walk 3-4 times during a 4-5 mile run and even once or twice during a 3 mile run. I have run 3-5 miles per day this week trying to use the MAF method and I am able to complete the run easily. I have also noticed that I am in a full sweat – – so it seems that I am in the “fat burning zone”. I would appreciate any input on what I can do to reach MAF so I can become an 8:15/mile for a half marathon. I have run numerous halfs and 4 full marathons. Thanks for any help that you can give me.

      • Arnie:

        The first and most important thing you can do is to stick with aerobic training for a while. Although going a few beats per minute over isn’t too bad, it’s best to keep your heart rate under MAF for as much of the run as possible. That’s the best way to ensure that you’ll be developing aerobically as fast as possible.

        • Arnie Cerny says:

          I have been following your advice and spending the vast majority of my runs in the 124-129 range (age 56 +5). What I have been doing lately, if the run is 3 miles, I have been running 3.6 or 3.5 and trying to pick up the pace the last .3 or .4 miles. My thinking is that I am getting the MAF method done for the prescribed mileage and then I am adding a little anaerobic work onto the end of the run. Is this okay?? My 129 pace is resulting in 13:30 miles – – how long will I need to be patient to where they are 8 minutes per mile??

          • Arnie:

            8 minutes per mile is extremely fast for someone with a regular VO2 max (of 55-65). To put this in perspective, it would have you running a half marathon at about 1h30min, supposing that you run a conservative 30 seconds under your 1st mile MAF. To run a half marathon like that (relying primarily on your aerobic system, as you should), you’ll need years of training. This is why serious athletes don’t really turn to racing the half marathon or marathon until they’ve spent years training (although they might run that distance for training or recreationally).

            To get there, it’s necessary to improve your biomechanics, form, breathing, mental game, strength, etc., as a supplement to aerobic training.

            Furthermore, don’t pick up your speed at the end of a run. Even while under MAF, you are still using muscle sugar to some extent. So, towards the end of a run, you have far less sugar in your muscles than at the beginning. This means that it takes far more out of your body to pick up your speed at the end of a run than at the beginning. (And don’t pick it up at the beginning, either).

            If you are really looking to go sub-8:00 MAF miles, you’ll really need to do some research on training principles, such as the principle of polarization. Essentially, this means that when you are doing an “aerobic workout,” you need to make sure the entire workout stays low-intensity. If not, your body will respond the same way that it responds to interval training: even though during intervals, perhaps 70% of the time is spent jogging slowly, far under the MAF HR, the body still takes that workout as a high-intensity workout, because the peak intensity was much higher than MAF. In other words, only go at a higher intensity on days that you do NOT want to count as “aerobic days.”

    • Adam Ortega says:

      Hello I’m having trouble looking for a good heart rate monitor I don’t care about the pricing, I been to sports stores and they don’t seem to have the knowledge of what I’m asking for, I want a heart rate monitor that beeps if I got over a certain heart rate, I don’t want to have a heart rate monitor that I have constantly look at to make sure that I don’t go over my maximum BPM

    • Andy says:

      Hi 50 year old just got back into running..So far lost a stone and half (very slowly), and now starting to use the 180 formula which just feels right to me..

      I’m following the 60 min foundation programme of yours on Pear, could you give me any recommendation on how long to follow that, and for how many days per week?

      Regards Andy

      PS Can’t wait for your new app any dates on its release

    • i’m 78 fitness age ?62? so MAF formula is 102 or possibly 118. This seems awfully low and produces very low performance
      train on c2 rower indoors 3 -4 times/ week
      warm up is about 120 bpm
      real exercise may go to 135 -145 for intervals that are 10 mins, with max when i make final effort ~166. Energy 650 cal/hr into machine on 10min + inervals, 850 cals/hour for 1m, 1,m rest; 1000cal/hr for every short bursts < minute

      so your formula does not make sense to me
      Please advise
      NO injuries, ~ colds/year

    • Markku Lehikoinen says:

      I have a problem opposite to Brian’s. My MAF pulse should be 180-65=115. I have set my heart rate monitor to 105-115. This causes two problems: Any ascend, however small, the heart rate monitor starts to complain (usually from 116 to 119, not more).In downhills the pulse rate tends to fall under 105. As a consequence, I will “never” achieve an average of 115. Usually it stays between between 105 and 110. Hence my question: Is the MAF pulse supposed to be an average, or a maximum?

  • Mona Minnie says:

    I think this may be the missing link for me. I have worked the last two years to address my muscle imbalances after years of being morbidly obese. Physical therapy and changing my way-of-eating has been life changing. I was just cleared for weight-lifting! I am going to invest in a heart-rate monitor now…any recommendations? Thank you for including my weight-loss transformation on your Success Page.

    • Ivan Rivera says:


      Hi, I’m moderating on the site. It’s great to read about your weightloss and fitness successes. Getting cleared for weightlifting is a great landmark!

      The 180-formula is a product of over a decade of research and clinical experience. If you figure out your MAF heart rate by following the formula and train accordingly you should continue to see huge health and performance benefits! Dr. Maffetone is a big fan of Polar heart rate monitors ( Chest-strap monitors tend to be the most accurate.

      You don’t have to run: hourly or half-hour stints on the exercise bike work wonders. Just remember to warm up and cool down appropriately for every workout. We’re coming out with an iOS app soon designed to help set and track health and fitness goals, based on the MAF method and the 180 formula. Stay tuned!

      • Mona Minnie says:

        Thank you. Oh good…I did get the Polar H7. For the 180-formula do you add 10 for each medicine taken? I take one medication regularly and another as needed. I have an Android phone so hopefully you’ll come out with an app for that. I could use the iOS app on my iPod Touch though. Also, how do we add an avatar? Thanks, Mona

  • Lee Michaels says:

    I am a fan of the Maffetone Method. I couldn’t believe how much fat I lost and how quickly my pace improved by training to a fixed heart rate and modifying my diet to paleo. Having 10-15 serves of fruit and veg has meant that i have stayed healthy while training for Ironman too. I’m in my mid 40s and on my 3-year journey from struggling to run 5 k’s to finishing in the top 5% in 2 Ironman events, a key to my results has been the Maffetone Method. However, I don’t use the methodology exclusively; if my improvement plateaus, i throw in speed work. Plus despite my increased aerobic fitness, when I cycle in the hills the effort becomes anaerobic. It is impossible for me to keep the heart rate below 140 BPM (I don’t even come close). Yet I see training in the hills as a key tenet of my success.

  • Heath says:

    Hi there,
    The first time I got onto Phil’s method was through a professional athlete I trained with a guy called Andrew Meikle when I was 14 odd. Andrew used to train all the time with a HRM and naturally I began asking questions. I think I had almost tried all formats of training and never worked at a very young age. Then he gave me one of Phil’s original books called ‘ everyone’s is an athlete’. I read this about a million times and applied the use of a HRM with his help and understanding. I still live and die by it now. Believe me, when you get that drop whilst running and your monitor tells you, hey mate, you now need to go faster at the same heart race pace…. Well,, that my friend is exactly when you realise Phil is a mastermind! What this training tells you is that your body is more efficient now and that means you can go faster because you went slower. Make sure you give it time, it really is amazing. I am a total convert for the last 25 years now and spread the word all the time. The new site is amazing and I think we all hope that Phil is still around shelling out his amazing guidance and wisdom. Would be great to meet him one day out here in Australia! we can only hope!

  • SteveL says:

    A number of years ago I found and adopted the MAF method of training. I went from like a 11:30 mile to a 9:50 over a period of about 9 months. But then i plateaued and then regressed all the way back without changing anything I can think of. The 180 method I believe works for most people but is there anyway to fine tune that aerobic heart rate number? One thing I noticed when I started with MAF is that I got nowhere with 180-age+5. It was only after adding an additional 3 beats that I then started making progress for at least nine months. I’m excited about the app and have signed up to be a beta tester.

  • Monika Bartalos says:

    Yesterday was the first time when I run using the 180 formula. I run for 10.5km at a 8:39 pace which was very slow comparing to my previous paces. First it was very challenging. There was an older woman over there doing some speed walking or nordic walking and she was faster than me :)) Nevermind, I kept continue on my slow pace having my HR on 150-155 ( I am 25 yers old). I felt very good during the whole run and finished full of energy. I can’t wait for the progression and better results! 🙂

    • Ivan Rivera says:

      Thanks for your comment, Monica! I’m an editor for Dr. Maffetone and I often help answer questions and comments on the blog. Sticking to the MAF heart rate takes a lot of conviction and willpower. Good for you that you’re managing. The benefits that you’ll see over time by following the MAF method will be nothing short of spectacular. Keep at it!

  • richard says:

    I don’t see what’s so revolutionary about this 180 formula. All it is doing is emphasizing base training at the proper zone 2 heart rate for endurance athletes, which puts you right in the fat burning zone. Not saying that your formula is wrong at all, but since we all have quite different max heart rates it seems no more accurate than the 212-age prediction for max HR.

    I’m 51, and have trained regularly for 3 years, so 180-51+5 gives 134.
    My max heart rate (based upon what I’ve hit in a bike race last year) is 186, so lets say my zone 2 endurance HR zone is 70% -75% that gives a range of 130 to 139.

    Did a 28k run and wore my HR monitor for 1st time in ages, just to monitor HR rather than running to a specific one, and was pleasantly surprised that HR stayed down in 130-140 range, even going up some significant hills it stayed down below 150. My usual endurance bike training zone would be in 130-140 range. Did 1st Iron man just over a year ago, kept my HR on bike at 140 +/-4 except for up hills where i kept it below 150. I did the ride in 5hrs 34, got off the bike and felt as like I’d not ridden I was so fresh, then amazed myself at doing a 3hr 44 marathon (1st marathon I’ve ever run).
    So I’m agreeing with you that base training works, train yourself so you can go faster at a lower heart rate.

    • Ivan Rivera says:

      Thanks for your comment, Richard!

      I’m an editor on the site.

      The revolutionary part about the 180-formula is that it takes into account your previous training and medical history to give you a better idea of what your aerobic heart rate zone really is. For example, since you subtract significant BPM if you’ve been overtrained or suffered chronic illnesses, or add BPM if you have been really athletic, it can potentially give you a number that’s quite different than what you would find with the 212-age or 220-age formulas. Since we all have a threshold heart rate after which we quickly climb into anaerobic work, even a few BPM can mark the difference between successful aerobic training and something else entirely.

      Since that threshold is tied to age as well as illness, stress, and overtraining, the 180-formula gives you a much more accurate vision of your particular aerobic zone than other formulas that don’t take health and fitness factors into account ever could.

  • SteveL says:

    When do you expect the app to be available for testing?

  • Lila Burnett says:

    Because this method is low intensity, how important is volume to continuing progress?

    • Ivan Rivera says:


      I’m an editor on the site.

      You need to do about as much as you would with any other training. If you’re just in it for the fitness, 1 hour 3 times a week (including 15 minutes for warm-up and cool-down), or if you’re competitive 1 hour 5 times a week. The more you do, you’ll see more benefits, but of course, if you do too much you’ll begin to see diminishing returns.

      There’s a bit of a misconception as regards athletic training: going at your max aerobic HR instead of a higher heart rate doesn’t mean that your training will be less effective, it just means that you’ll be training your aerobic system instead of your anaerobic system.

      In other words, the aerobic system–which is the most important energy system of the body–can’t be trained as effectively at higher heart rates. That’s why all elite athletes do 80% of their training at an easy speed or intensity: they (and their coaches) know the importance of aerobic development. It’s usually the non-elites that do 60 to 80% of their training more intensely in an effort to “catch up.” But the body’s just not built for that, so they get hurt.

      I hope I’ve answered your question.


  • Ryan P says:

    I was pointed to the site by a colleague of mine. After perusing and reading what I thought was pretty revolutionary to me, since I had never been exposed to lower heart rate training before (no pain, no gain, right?), I bought a heart rate monitor and started training right.

    After 10 years of not being able to run between intermittent lower back pain and exercise-induced asthma issues, I had tried to run again, with miserably slow results and no improvement after 6 months. In the three months since I have started MAF training using Dr. Maffetone’s low heart rate techniques, coupled with some positive diet changes, not only have I improved significantly in my run time, but have also lost 20 pounds when I didn’t think I had much to lose. I am still base building, and will probably continue to do so for the next 6-10 months, as my time continues to improve.

    I ran my first 5k last weekend and (surprisingly enough to me), despite allowing my heart rate to rise above the MAF threshold for the first time (and by a considerable amount, even), I had no breathing difficulties at all, and even finished the 5k faster than I had anticipated. I’m continuing to train for longer races, and running about an hour per day, 5-6 days per week. The most important parts of all this are:

    I haven’t had any breathing difficulties while running for the last three months since starting low heart rate training using Dr. Maffetone’s guidance, and
    I haven’t had any lower back pain in the last three months

    Other health benefits include:
    My intermittent headaches are gone
    No more migraines
    Lost 20 pounds
    Better night vision
    No random leg aches and pains
    No sugar cravings
    No bowel irritability, thanks to cutting excess carbs
    No more insomnia
    Better stress management
    I actually enjoy running now, which has never been the case before
    I’m healthier now than I’ve ever been before!

    I’m hooked. I bought the Maffetone Method and the big book of endurance training and racing. I’m training up for some longer distance races now, but taking my time, of course. My first half marathon will be next February, though I think I’ll probably be ready for it before then. Thanks again for everything.

  • dmz says:

    According to the formula, at 51 (180-51) and taking medicine (-10) for asthma(-5), my MAF number is a whopping 114. This means I don’t get to run at all. Ever. My true VERY easy effort feel is 130’s-140’s. max HR 205, resting HR 44 & have 2 recent BQ’s, 22 ultras and marathons, 90+ races last 5 yrs, not at all injury-prone, plenty of success and improvement, only 9 consecutive days lost on 2 occasions (50+ mile ultra recoveries). I believe the formula is too inflexible for older, well-conditioned, but naturally high heart rate runners with strong aerobic bases from years of ultra and marathon training. My 50 miler are raced at 145-150 HRs, marathons are neg split, no wall, no fade averaging 168-170 and I get almost no drift upward in HR during 26.2+ races. If I could dedicate a time block to MAF, it would have to be something well beyond 114, 129-139 would be my guess.

    • Ivan Rivera says:


      Thanks for your comment. I’m an editor on the site. The 180-formula gives you the maximum heart rate at which you’re likely to be functioning completely aerobically. Despite the fact that your perceived effort is minimum at the 130, most likely you’re using your anaerobic system. You may be extremely resilient and far from overtraining or injury as you train. That said, if you don’t go at your MAF heart rate, it’s likely that you won’t be developing your aerobic base at the fullest extent.

      If you do, however, you’ll most likely see your speed to climb quickly, particularly if you’re not injured or overtrained.

      I hope this helps. Please shoot back with any questions or comments.


      • SteveL says:

        Ivan: What I’m wondering based on what DMZ stated above is there a treadmill test or a track test that can be used to dial in the MAF a bit better than the 180 equation? I’m sure there are people who are outside the say 80% of people whom the 180 formula works really well but there may be those of us who are at either end. Is there a treadmill test that can help here and if so what should one look for in that testing? Thanks!

      • Ryan P says:

        Ivan, dmz,
        I just want to add that when computing the 180 formula, the directions listed above say:

        Modify this number by selecting among the following categories the one that best matches your fitness and health

        The one factor that best matches is probably -10 if you use a daily corticosteroid such as Advair, or -5 for asthma if you only ever use a rescue inhaler as needed and not daily. Use that to amend the (180-age) total, which means dmz would be 180-51-10=119 if he uses a daily medication, or 180-51-5=124 if not. 5-10 bpm doesn’t seem like a lot of difference, but it is. And yes, even at 119 you would eventually be able to run at your current race pace after base building adequately.

        I personally only subtracted 5 instead of 10 from mine, 180-32-5=143, as I have exercise-induced asthma, but I have no need to take medication for it so long as I keep my heart rate down.

        Although with your training history, I don’t know. You can never out-train the fact that you have asthma, but there is obviously a bit of conditioning going into it too, and your physiological age may be younger than your chronological age in reality due to your training history and lack of injuries. I feel like if you fully understand the reasons behind the adding or subtracting to/from the 180 formula (which is to adjust for physiological vs chronological age), you may find that you would have to add a few or leave it at 129 after all.

  • Judith Kay says:

    I am 63 and am using your 180-HR rate; I had my aortic valve replaced with a turbo-charged, chrome-wheeled On-X mechanical valve 18 months ago. I don’t take any heart or BP meds, but am on other meds such as warfarin and synthroid. I find it very difficult to keep a controlled 107 HR without being on a treadmill. Outdoors, walking flat can leave my HR in the high 90’s; an uphill can easily zoom me into the 120s’. Is it okay to have this big a range or should I stick with the machine that can get my HR in a range closer to my target? I stop on the hills until my HR drops, but this involves alot of monitoring. I really appreciate Phil’s relaxed tone about walking being aerobic and having a training HR this low.

    • Larry says:

      Hi Judith,

      I am a week into my MAF training. I have a fancy mechanical aortic valve too. As you can imagine I was very excited to find your Q as I read down the Q&A. (I suspect we may be too ‘medical’ for an answer. I didn’t see an answer, anyway.)
      My question to you is, have you kept up the training? And if so, how is it going? I am in a similar situation to your’s in your question as far as the walking and running. I am using an indoor bike trainer for my starting point in hopes of evolving to the low HR running. Looking forward to my next test!

      Take care,

  • Kurt says:

    While listening to Dr. Maffetone on a podcast I heard him talking about watching athletes train after various types of meals. I have experienced his observations with my own n=1. If I’ve had too many carbs for the day before starting my workout, my heart rate jumps up too easily and I spend more time walking. With a good sensible meal plan throughout the day my workout is more enjoyable and feels easier even though I’m jogging more of the time. I even feel more relaxed!

  • SteveL says:

    So I used the beta version of the app the other night. Where do we report things as we use it? I already have one item for usability.

  • DDC says:

    Reading all of Dr. Maffetone’s writing as well as the above questions from Brian Fay, dmz, and SteveL…

    I’ve never heard Dr. Maffetone articulate why the 180 formula does not consider your maximum heart rate. Why doesn’t your max heart rate affect where your aerobic vs anaerobic crossover is?

  • Dan says:

    I’m a 74 years old male. My resting heart rate is around 70. Just walking around in my house my heart rate is in the 90’s. The route I walk is an up and down gentle sloop at a 20 minute/miles pace which starts off at 105bpm(down hill) then picks up and varies from 116 to 136. I find that raking the lawn will bring my heart up to the 130’s. Shoveling will bring it to the 140’s to 150’s. I’ve read that some people have a normal heart rate that can be much higher than what is considered normal. I’m I one of them?

    • Dan:

      Thanks for commenting. It’s very hard to know whether a high heart rate is “normal” for you without a very detailed medical examination and previous knowledge of all your medical history and activity background. Since most people old and young have severely underdeveloped aerobic systems, it’s more likely that the rapidly rising heartbeat is caused by a lack of aerobic ability.

  • pdiddy says:

    Found this through Natural Born Heroes, then bought the Maffetone Method and now reading the Guide. Great stuff.

    I’d really appreciate some feedback on my experience with the method (Ivan).

    Quick background: 46 years old and what would generally be considered in shape. Exercise pretty much every day, probably about 15% body fat. Paleo diet. Highly varied workout: martial arts, weights, bodyweight training and running is a part of that, but not huge. Also occasionally hike, kayak, play tennis, SUP — I’m active.

    I can pretty easily run 9 minute miles and last fall I did a 5k in 23:54.

    BUT, like so many people I can’t believe how slow I have to go to keep my hr between 124 and 134.

    Question 1: The difference between my comfortable anaerobic run speed and my time using the 180-age method seems huge. After 3 weeks I’m doing like 15 minute miles — as opposed to a 9.

    I heard Dr. Phil saying on the Primal Endurance podcast that “if you’re doing 8 minute miles, you might be upset to see your speed reduced to 9:30 under this method.” My differential is WAY bigger than that!

    Is it just that I am really THAT de-conditioned aerobically? I suspect the answer is a (sympathetic) “yes”, but would appreciate the feed back.

    Question 2: So I get that I’ve got to keep my hr under the MAF, in my case 134.

    The problem: my hr will go right from 132 to 142 in SECONDS! I mean I look at my Garmin Forerunner one second and say “cool – 132” and literally 2 second later it says 142!

    Of course I immediately go down to a walk and my hr comes back down pretty quickly.

    But still, sometimes my hr continues to go up for a few seconds after I stop jogging — sometimes 150.

    (And I’m not running hard! I’m just barely out of a walk.)

    Is that a big deal? If so, how I can stop that from happening?

    And yes I warm up like he says (and cool down).

    If the answer is “just walk” I don’t think that is the answer because I can walk all day and never get about 124!

    I think I have a conditioned response where as soon as I go from a walk to a jog, my brain tells my heart “faster!” Anything to that?

    Much appreciate any feedback Ivan!

    • Pdiddy:

      Thanks for commenting.

      Some of us are conditioned awfully badly, I’m sorry to say. In my case, I’ve been training by the MAF method and I’m running 8:50 minute miles. My usual tempo pace is 6:45. So I understand how you feel. What I do is I train ~5 BPM below my MAF heart rate, in order to allow for any variability. And of course, sometimes my heart rate also jumps beyond my MAF limit. But you don’t have to worry too much about it. Just slow your pace a little bit, and in a few seconds you’ll see that it starts to come down.

      As to the question of why your heart rate jumps from walking to running, well the short answer to that is because running has a flight phase. When you’re walking, your body is using primarily your bones for support; your muscles are used primarily for movement. But when you’re running, your body has to contract all of your leg muscles powerfully in order to stabilize your knee as you land. In other words, even though your speed increase might be minimal, your muscle contractions are much more powerful just because there’s a flight phase and a landing phase involved in running, and your muscles have to provide support in addition to movement.

      (Your heart rate also jumps to make up for this sharp increase in muscle contractions).

      In other words, there’s really no way to avoid this leap.

      Hope this helps.

  • SteveL says:

    pdiddy: When I started this a number of years ago I had to slow way way down. It seemed stupid at the time and I would even get angry at how slow I had to run. I had a terrible time locking in my heart rate. I ended up increasing the MAF HR from 180-Age+5=MAF to +8 instead of +5 and I was able to lock in my HR even though I was still REALLY slow, but over a period of 9 months I got faster and faster. I did learn not to do a MAF check every week as that just lead to frustration and I started doing them every three to four weeks just like he um…said to do!

    • pdiddy says:

      Thanks both. Just the feedback I wanted.

      I tried going -5 on the 180-age formula this morning. It did stop me from going too far over my actual 180-age. I did a few times as a result of the lag time between when i stopped jogging and when my heart responded to that — but far less than before.

      Of course that meant that I am now doing 17-18 minute miles instead of the 9 minute miles I previously found comfortable!!

      Honestly, I counted it out and was able to take 7 strides at a slow jog before having to stop. If I took the 8th stride, my HR would still be in the 120’s, but after I stopped walking, it would go all the way up to 143 or something!

      7 strides jogging, and then maybe 10 walking is kind of frustrating. I’d run slower but I really cannot go slower without walking! Like I said, I’m doing 17-18 minute miles so honestly, I’m not moving fast at any time!!

      I’m still a little skeptical to be honest, but your advice will help me to continue with this experiment.

      I can see that, yes, notwithstanding my good conditioning in many ways, I am de-conditioned aerobically. In fact, today I admitted that even though I can run 4 miles in less than 36 minutes, walking up to my third floor office actually does wind me a little bit. It has for some time actually.

      I’m excited to correct this imbalance and always happy to have a new fitness challenge.

      Thanks again!

      • Pdiddy:

        Thanks for your continued involvement.

        One thing I recommend is that you do your MAF work on the exercise bike, as well as walking. Or, if you own a jump rope, try doing it while jump roping. That will help develop the aerobic system without the added shock of landing (jump-roping has very little shock as compared to running, since there is no forward motion “stopping” component), meaning that your heart rate won’t kick up as far. Jumping rope should kick it up a little more than cycling, however.

        The sad thing is that people’s aerobic system is just that underdeveloped. This is not just you—it’s the case with everyone, even elite athletes.

        Remember that your aerobic system is getting developed in relation to your heart rate, not your speed. As it develops, your speed will begin to rise naturally. It’s important to allow these gains to be made on their own time.

        • pdiddy says:

          Great suggestion Ivan!

          I tried the exercise bike this a.m.

          I might be an oddball!

          My perceived effort level in the runs I described before was like a 1-2. On the bike: like 7-8! I was sweating and breathing hard. There was no way I was going over 134 bpm, that would have required tremendous exertion.

          I’ve experienced this before, years back, where I would deliberately try to get into the anaerobic range on the bike and feel like it was trying to kill me. Meanwhile, I could do that on a run and feel fine!

          Most likely it is that I just haven’t really developed the leg muscles for cycling and so it is harder work.

          But it was good to break a sweat and breathe a little!

          I think what I will do for a while is just kind of alternate the exercise bike and “runs”.

          Obviously I’m very open to suggestions though!

          Thanks again.

          PS I also correlated my garmin hrm with the one on the bike — they’re pretty close, so that is good to know.

  • Jessica says:

    I’m just getting back into running after years of being mia, so I might as well be a beginner. I am 33 and on a thyroid medication. So my rate would be (180-33)-10 = 137?

    If I can’t keep between 132-137 by running/jogging, do I start with fast walking and then progress up? Also, I have an elliptigo that I would love to incorporate as part of my cross-training. Would I need to make any adjustments to my rate for those workouts? Also, jump roping was mentioned above. Is that something that should be incorporated for a beginner?


    • Jessica:

      Staying at (or just below) the MAF heart rate is the most important thing. You don’t really have to make any adjustments sportswise. What you’ll notice, however, is that your heart rate rises a lot faster with running than it does with other sports, because of the flight and landing. So jumping rope is kind of a way to bridge the gap between cycling, elliptigo and running (it has a landing component, but is nowhere near as intense as running). Elliptigo is a great aerobic tool, and it also helps train a lot of the components of the running gait without the associated flight and impact.

      Your MAF heart rate would be 137.

    • pdiddy says:

      What I love about this system by the way is that it keeps the “how hard can I push myself” factor out of the equation.

      If my times are getting better, it is because I am getting fitter, not just because I’m grinding harder.

      And yes, I am someone who will run myself into the ground to do 10 seconds better on a training run, so this is important!

    • Amanda says:

      I will try the bike too! I can’t walk fast enough to get my HR to 140 but I also can’t run slowly enough to keep it there. About 10-20 strides into a very slow jog and my HR begins to climb quickly. Then I go back to walking and it drops quickly to 120.
      Thanks for the advice!

      • Lauren says:

        I have this problem too, even worse is that I trail run and up hills even walking can push me well past the threshold, however on flat ground I can’t walk fast enough but can’t run/jog slow enough to keep a consistent rate. It’s hard to know if I’m even doing it right! Good luck to you, I’m hoping after several weeks of doing this 4x a week I’ll start to see improvement in my pace with keeping that HR below my limit.

    • Pdiddy says:

      Just a quick progress update if you’re interested.

      I (stupidly) pulled a calf and was out of commission for most of a month in terms of running. Still ran. (I stepped on a very pointy large rock running in VFFs, foot didn’t hurt TOO bad, so I kept running — with an altered gait. That was the stupid part!)

      Got a new HRM and that has made a HUGE difference!! The old one was ok one day, whacky the next. Finally just chucked it in the bushes when I got home from a run.

      But I’m cruising now! Thanks.

    • brianw says:

      I’ve been trying the method for a few weeks now, with a HRM and am 47. I’m a lifetime runner and am in moderate shape right now. I ran a 43 second 440 in high school and a 4:20 mile, so have wheels, but now would go and train at about a 7 minute mile and feel good. On this method, I am having to run a 10 minute mile to stay below 133. I’m almost walking. And after only a few weeks I see no difference. One thing I’ve haven’t seen is about distance. My short runs on 3 miles right now, and longer runs are 5-6.

      Honestly, it is taking all the fun out of running to run this slow. Can I reasonably expect improvement soon? I eat pretty Paleo, and have a resting heart rate of low 50’s and high 40’s.

  • Natasha says:

    Hi, I am a runner who uses HR training. I am 40 yrs old. The question I have it, so it I want to incorporate low-key tempo intervals at 80%, what is my HR range for that? My Max according to your formula is 140 BPM. Thanks for your help!

    • Natasha:

      It’s important to remember that your MAF heart rate isn’t necessarily related to measures such as the anaerobic (lactate) threshold. So going by 80% of your maximum heart rate (220-age) is sufficient, unless you are an elite athlete and have access to your blood lactate info and so forth.

  • Mystery says:

    Hi, I play a variety of sports year-round, and change with the seasons. So I’m trying to figure out how I might be able to integrate this approach (if possible) without stopping my other sports. Typically I play a couple times a week a sport that will have mostly anaerobic demands (e.g. ultimate frisbee, ball hockey). Also, could I do something else other than running, but keep the target rate going -e.g. swimming?

    • Mystery:

      The MAF heart rate is the same across all sports. You can do whatever you want, even weightlifting, as long as you stay at your MAF heart rate.

      • Keith says:

        Hopefully you’ll get this Ivan, in reference to Mystery’s post, he spoke about high demand anaerobic sports. I play hockey 2-3 times a week. My MAF HR is 134-144. During hockey, my HR will rise to 186 for about a minute, then decline to 120’s-130’s for about 2 minutes, on average. Will this hinder my progress in MAF? If so, to the point that I should look into a different training method?

        • Hi Keith,

          It’s a great question. What you want to do is ultimately train for the sport you want to practice. MAF training is not just about getting good at endurance, it is about developing an aerobic system that can support and absorb the stresses of anaerobic activity in any sport. So if you add MAF training, even though you may not progress as quickly as someone who didn’t do anaerobic exercise, it’ll still help you absorb, process, and become more resilient to its effects. This translates to less fatigue during a game, better recovery afterwards, and a better overall training response.

  • Robby says:

    I discovered MAF training in 2003 while preparing for my first half ironman, it was a breath of fresh air. Since then, I have looked at and used every method available but I continue to come back. I love it for several reasons. One, very low injury rate. Two, allows for individuality. Three, brings joy to training and four, it’s a self evaluating system; i.e. if you’re not making progress, something is off, eating, sleeping, Iron etc. Being a coach, this is the method I used for myself and endurance clients.

  • Natasha says:

    Thanks Ivan. I have been using the 205.8-.685 x age formula, then multiply it by .8 for 80%. Is this correct?

  • Sebastian says:


    Please let me start from thanking Dr. Phil for the MAF method and the Big book of endurance training and racing. This is truly an awesome book.

    I would like to ask you if the maximum aerobic heart rate can be established not following the 180 formula? I mean based on results from a real testing at physiology lab or even using Friel’s method.

    Thank you,

    • Sebastian:

      Absolutely. In fact, the 180-Formula was derived in order to be able to reproduce observations about aerobic function made in the clinic/lab in an easier format. However, I’m not sure what other methods may be able to give accurate results, since a lot of observations from a lot of domains are needed to ascertain the MAF heart rate. We are currently working on designing other methods of figuring out the MAF heart rate.

  • Jonathan says:

    I have doing the 180 method for about 3 weeks now, my biggest question is regarding cadence. I am really finding it hard to keep my cadence up and my heart rate down. Do you have any advise about this, I know you are going to say I must say in HR range, but should I forget about cadence at this time or try to get both. I had a perfect 90 steps per minute cadence before starting, now I am around 78-84.

    Also a second question, when running up hills obviously your heart rate pick up, would you suggest staying away from hill or still use them and go very slow to keep the heart rate in zone?

    • Jonathan:

      Cadence typically lowers at lower speeds. There are theories that say that cadence must have an absolute minimum of 88 steps per minute. However, you’ll rarely see this cadence maintained above 8 minute miles.

      Just go slower on hills, or walk if you have to. If you’re able to maintain a running form, you’ll see your hill speed begin to rise in a couple of weeks.

      • Jonathan says:

        Thanks for the reply.

      • Bill Dycus says:

        Can you clarify this a little further? When you say just go slower on hills, are you talking about pace or cadence? Is it okay to sacrifice cadence right now while we are base-building, or should we try to keep cadence and take really small steps?

        • Bill:

          When your cadence drops below a critical threshold (which varies from person to person), you start putting too much stress on your knees. That said, it is fine to sacrifice a little cadence—in fact, it is natural for cadence to rise as you pick up speed. What you want to avoid are those classic heavy, slow steps. Pick your feet up, keep your cadence brisk, and keep your head, shoulders, hips, and feet (as they land) “stacked,” but there’s no need to overdo it.

          As long as your run feels supple and you’re light on your feet, you’re doing 80% of what you need. That final 20% is important, but it usually has to do with things that pertain to someone’s particular mistakes, not general issues with form.

  • Emily says:

    Hello! For the table with MAF, 5K race pace and 5K race time, I was wondering where the number on the left hand side is taken from? Is it the average split from all the recorded splits of the MAF test? Or the last split of the workout?
    Thank you!

  • Jenny says:

    I wondered if the number changes at altitude. I live at 8700 feet, and everything is up from there, so I often run/walk at 9000 feet and above. Should I adjust my target rate? Thanks.

    • Jenny:

      Great question. The heart rate remains the same across altitude. A way to think about it is that what you want to do is make sure the aerobic system is functioning at 100 percent, with as little anaerobic work as possible. A higher heart rate is tied to greater stress, which means that the body is doing more anaerobic work. Because of that, the level of aerobic/anaerobic function is more dependent on heart rate than it is on any other variable.

  • Mike says:

    When base building, does anaerobic activity just forestall using predominately fat for fuel or completely inhibit it? My MAF heart rate is 122 and climbing stairs and mowing the lawn can put me over that quickly. Doesn’t seem reasonable to remove daily activities because they could be slightly anaerobic. Is there a compromise? I like the idea of developing an aerobic base, but not to the detriment of necessary daily work activity.

    • Mike:

      Thakns for your comment. Anaerobic activity doesn’t completely forestall base building. Don’t remove daily activities. Your base-building won’t be as fast as it could be, but it’s safe to say that you won’t be at risk for overtraining during that period. You’ll likely find that after a while, you’ll be doing all the activities you mention at your MAF heart rate.

  • Mike says:

    Is it still possible to build an aerobic base when daily activities like climbing stairs and mowing the lawn push up heart rate with moderate exertion? My MAF heart rate is 122 and it easily jumps into anaerobic zone with these activities. Interest in developing an aerobic base that burns more fat. Thanks.

    • Mike:

      Thanks for your comment.

      Daily activities, even if they go slightly above the MAF HR, will still strongly develop an aerobic base. The reason that we stress the MAF heart rate so much is that many people ONLY train at a heart rate that is 20 heart beats above that heart rate. So, if you’re doing housework or yard work, don’t worry about it. You’ll be getting many of the same benefits.

  • Alex M says:


    I am just starting out with MAF training (gosh it is slow!)

    How long do I have to keep training with my HR <145? Am I just supposed to continue indefinitely training at this HR and hope for my speed to pick up while maintaining this HR?

    The article says you will not be stuck training at this pace for too long. Is that because my speed will improve or because there is an end point to training at this HR? Hope that made sense.


    • Alex:

      You won’t be at that training pace because your speed will improve. For example, in a 12-month period, people have seen improvements of 8-10 minutes in their 5k pace, while remaining at the same heart rate. That said, once you have a few months of exclusive training at the MAF heart rate, it’s ok for your training to be 20% anaerobic.

      It really doesn’t take more than 20% to gain the maximum benefits from anaerobic work, and it doesn’t take more than 30% of anaerobic work for your risk of injury or overtraining to begin to climb steeply.

      • Melissa says:

        I read a lot of and searched through the comments, so I hope I’m not asking the exact same thing as someone else…. I’m just hoping to ensure that I’ve got this completely straight!

        It doesn’t matter how far you’re running on any given day or what distance (race) you might be training for. You just do ALL of your runs as at your calculated heart rate for several months. That is, the ONLY limit” is your heart rate, not amount of time running, distance covered, etc….?
        Also, could you define “several months”? I totally DIG the idea of slowing down to get faster and doing that nearly all the time. But I do enjoy the occasional track workout just to make it interesting.


        • Melissa:

          Basically. And several months typically means “no less than 3” and “maybe more than 6.” However, if your MAF speed happens to be at around the 7 minute mile mark, you don’t really need to worry about building an aerobic base: its’ already well-developed. That said, 80% of your workouts still need to be at your MAF heart rate.

          If you want to make it interesting, one of the things you can do is shake the MAF runs themselves up by sprinting only for 10 yards and then quickly scale back to your MAF heart rate. However, do this as sparingly as possible.

          • Melissa says:

            Thanks a million!

            I’m nowhere near that 7 minute thing. I’m thinking that puts me in “maybe more than 6” range.

            Thanks for the tips. I’m excited about this!

  • […] uses the 180 formula developed by Dr. Phil […]

  • Olivier says:

    Hi everyone,
    I’d like to bump pdiddy’s post as I am exactly in the same situation, same age, same perceived level of fitness, even same Garmin HRM!
    My heart rate has been jumping up and down exactly the same way, and at the moment, I can’t even run (or like pdiddy, a few running strides, then walk …etc).
    Now, I know my aerobic level is not great, although my running times are ok (23mins on 5k, 50 on 10k …etc).
    I want to add the following: I started the MAF test 1 week ago, with 0 carbs 0 sugar at all. During my first 1h run 1 week ago, I was able to run about 75% of the time and stay in the MAF zone (124-134), then the next run, 50%; then the next one (1h30mins), 33% run and the rest walk, and finally this morning, I’m probably 10% run and the rest is walking (and when I say run, it’s mostly slooooo jog for a few strides).
    I’m wondering if the 2-weeks MAF test also affects my heart rate so drastically. I have 1 week to go so I won’t worry too much if that’s really the case, but moving forward, if I can’t run, how will I keep my running “muscles” working if I actually can’t run?
    I will try the bike as pdiddy mentioned but running keeps me sane 🙂
    Please share any advice!

    • Olivier:

      You can try jump-roping; that will help you keep the running gait movements. But since the two-week test cuts back so drastically on your carbs, it’s very difficult to stay running at the same heart rate without a very powerful aerobic system. Once you start experimenting with carbs again after the test, you should see your speed pick back up.

      • SteveL says:

        Ivan I also wonder once Oliver’s body flips to burning fat for fuel if his run time will start to rise again? He may be a heavy sugar burner. Thoughts?

        • Steve:

          Absolutely. The more powerful a fatburner you are, the faster you will go aerobically. The problem is that when you take away carbs from someone who is currently a sugar-burner, they will see that drop in their speed. That should be less and less so for a fat-burner (unless, of course, you are asking for anaerobic speeds from them).

          • Olivier says:

            Thanks so much all for your response. I was starting to wonder if my HRM was getting interferences … I tried the bike this morning and was able to get a good sweat so this is reassuring. I will try the rope. I was expecting my speed to be slow, but not that bad though, along with the test, that’s definitely harder so I guess I will see after the test; however, I kind of feel good so I want to keep my carbs intake very low even after the test. Thank you again for reassuring me, this is such a shock that I’m having a hard time understanding what’s going on so I question everything. I will update this post when I’m back to some carbs next week in case that may help other people.

  • Garret Adkins says:

    What kind of adjustments if any should be made for smokers?

  • James Lavin says:

    Being repetitious of the other comments, I still wonder if this truly translates to older athletes. At 60 the base formula brings me to 120. I’ve been running for 48 years. I can sustain an average heart rate of 160 for 6 hours during a race and slowly drop thereafter, but still can average 150 for 10+ hours without feeling stressed (except my quads) so I can’t see how that isn’t aerobic. I have done LSD training in the past, and I can agree that limiting to 135 would be good training for the next few months, but 120??……

    • James:

      The 180-formula has been extensively corroborated clinically (with more than a decade of research). It works in virtually every case that has been studied.

      Going at 150 may be aerobic, but it may not be fullyaerobic in the sense that it may not be sustainable. In other words, you may still be substantially using your anaerobic system to maintain that pace. In other words, the stress will begin to add up if you do this every day.

      That said, there are certain caveats if you are over 65 years of age: You can add 10 BPM if you’re in good health.

  • Jay says:

    Thank you Phil,
    I will be 80 years old in September. Was a pretty successful competitive runner for over 40 years. Started having a lot of leg muscle soreness, especially around hips. Thought I might need hip replacements or some other fool thing. Began studying the 180 formula and am starting out slow and will keep the aerobic level from now on. Will post my successes and failures over the next year. Have been riding 25-50 miles on my bike three days a week since cutting out the running over the last year. Have missed the runs. Going back to the LSD practice now and hope be back to long trail running by 2016. Smiles out to all of you folks who are ageing strong.

  • Alex M says:

    Thanks for your previous reply & great work on replying to everyone in such a timely manner- cudos.

    I have just started training for an Iron Man. How do I integrate the speed sessions in? For example in my swimming there might be 4x25m fast pace sprints or in the running some 30sec pace increases. Would you advise I leave these out? Or until later in the program when my pace/HR has improved after some exclusive MAF only training?


    • Alex:

      If you’re not overtrained (or feeling like you’re constantly on the redline), or haven’t been injured in a while, I’d say that your anaerobic training volume should be 20% of your total training volume. That said, your aerobic base won’t develop as fast unless you do a period of exclusive aerobic training. If you don’t have any health or fitness issues, what I would do is wait for the off-season to do exclusive aerobic base building. That said, Mark Allen did near-exclusive aerobic training for a long time.

  • Michael says:

    Im 42 years old this year, in the maffetone 180 formula my max hr should be at 138.
    My question is if i turn 43 next year should i adjust my max hr? Should i change it yearly? Thanks

  • Olivier says:

    Hi MAF community,
    I wanted to update my previous post regarding my hrm yoyo-ing in a funny way. As I’m just completing my two week test, during which I thought that was kind of normal that my heart rate would just jump from 120 to 152 in 2 secs; this combined with what I thought was a bad aerobic base, I left it and resigned to the fact that I could not run at all, just walk. A few days ago, as I was warming up inside before going out, I was just slowly walking up and down stairs, then simulating rope jumping. Stairs were fine but then jumping would make the hrm jump as well up to 170 in a matter of second. Something was wrong obviously. Tried different things, including re-adjusting the strap (to the tightest), humidifying the electrodes, replaced the battery … until I just push the left electrode to my chest with my right hand, boom, the hr would go down instantly to a more reasonable number.
    Long story short … don’t always trust your hrm. Now, I’ve been out 3 times, and after warm up, the hrm is more stable although I still need to press the left electrode with my hand when it jumps too fast (then it goes back down instantly) but at least I can now run and the numbers make more sense now. I can sustain a run to a reasonable pace, still slow but that’s expected as I’m slowly rebuilding my aerobic base. Phew. I’m now looking for a new hrm as it’s quite frustrating to have to readjust the strap and press it every 10mins … any suggestions for a new STRAPLESS hrm? (forerunner 225 looks neat).
    Thanks for maintaining this website; this is so helpful!

  • Ken D says:

    Just had a question about heart monitors in general. Does Dr. Maffetone have a preference of heart monitors? One that might be better than the others. I ask this because I have a Tom Tom and at times my heart rate will be right in the aerobic zone at a pace I might have been holding 10-15 minutes. All of a sudden it will jump from 130 or so to 160 something 180 sometimes as high as 216. I get a little frustrated because I don’t know what caused the major elevation. I start walking it comes down well below my max and I start running sometimes it will take off again. Other times my normal aerobic pace will be reflected correctly on watch. Long question. Is my watch being glitchy or is my body enduring a stress? At those high heart rates it would seem like I’m sprinting but I’m actually running slow pace. Anyway, need some guidance. Thanks

  • Gerald says:

    While I completely agree with the concept of training in a particular heart rate and thus improve the aerobic base, i am of the understanding that aerobic and anaerobic cannot be compartmentalised. I believe that running at threshold most of the times improves your aerobic fitness also and viceversa because without an adequate aerobic base running at threshold for about an hour may not be possible. One more aspect is the recovery between intervals. Doesnt quick recovery between repetitions indicate good aerobic endurance. My point is by doing threshold and anaerobic doesnt the aerobic capacity also improve simultaneously.

  • […] Maffetone Method defines a simple way to ensure you are training at your maximum aerobic function. The formula […]

  • Shardul says:


    I just started with MAF a week back, my age is 40 , and have been running consistently for 2 years , did 2 half marathons , so my Ideal HR zone should it fall between 135 to 145 or 145 to 155 .

    As of currently i can comfortably run 10 K at 6.3 to 6 pace , completing in 1 hour to 63 minutes

    I am a newbie in MAF , so needed little advice

    • Shardul:

      Start by doing the 180-formula. Run 5 times a week. I recommend starting by doing 1h15min workouts: 15 minute warm up at 20 BPM below MAF HR, run 45 minutes at MAF HR, and cool down 15 minutes 20 BPM below MAF HR.

  • Paul says:

    Am 68 most likely have been over training my entire life. I enjoy running trails and longer distances. Unfortunately in the last couple of years I’ve been unable to maintain a good base mileage. I’d love to be in the 35-60 mileage range. I do Pilates about 6 times a month with a personal trainer and TRX 3 times a month also with a personal trainer. I also do Elliptical with Ifit trails and alsohave an elliptical which I can take on the streets. I’m very excited about this new training method and look forward to many more years of great trail running and racing.
    Thank you for renewed life

  • Mike says:


    I have a body composition monitor which tells me I have a metabolic age of 42 versus my chronological age of 48. Which is the better ‘age’ to use when applying the 180 formula?

    Thanks very much.


      • Sean Rodgers says:

        How can I determine my metabolic age? I’ve trained with HR for over a year now (returning from a stress fracture for 3 months now). I’m down to running a 5K at <140 @ 9:35/mi average pace. I started back @ 10:15/mi.
        I'm 48 and I've been running for 9 years including marathons and Ultra's.

  • Kathie says:

    Hi! I just started Barefoot running and came across this method via Natural Born Heroes. Any particular advice for a new runner? (age 57, female.)


    • Build your aerobic base first, by using the 180-formula and the MAF test. I wouldn’t worry about form, speed, or races until at least a year of training and understanding your body.

      • Vinny says:

        Hello- I love the whole concept and have been training for a few months aerobically and feel great. I was wondering g-what do you feel about other factors such as heat or dehydration that can alter my heart rate ? Should I just stick to formula and assume that is a stress on my body that is accounted for? Some have said to go by feel because of this.
        Hope you reply!

        • Vinny:

          Here is an excellent article detailing what any and all stresses mean for the body.

          The short of it is that heat stress, cold stress, anticipated threats, etc. all cause the body to begin expending more energy. (If the aerobic system cannot provide that much energy, the body has to go anaerobic). So every single time, no matter what, an increase in heart rate points to a corresponding increase in energy use.

          So yes, the MAF HR factors all stresses in.

  • Does your resting heart-rate matter at all in using the formula? I have a resting heart rate in low 50’s. Intuitively, it would seem like someone with a very low resting heart rate should therefore have a correspondingly lower MAF rate compared to someone with a resting heart rate in the high 70’s, for example. Yet unless I’ve missed it, the formula doesn’t take baseline HR into account at all. But perhaps I misunderstand the logic/physiology behind the formula.

    • I wouldn’t call RHR “baseline.” Resting heart rate fluctuates very easily: for example, it changes depending on how stressed someone is. For example someone with chronic stress may even have a resting heart rate close to the 90s. This is because they are using a lot of anaerobic activity to keep their body going. The same goes for someone with a poor aerobic system: when the aerobic system can’t sustain the body with fats alone, it appeals to the anaerobic system.

      Conversely, an elite endurance athlete may have a RHR in the mid-30s because they have highly developed their aerobic systems. In other words, their aerobic development means that they have a much wider aerobic range, than say an identical athlete whose RHR is in the mid-40s. If both athletes have a MAF HR of 155, one athlete would have an aerobic range of 120, while the other would have an aerobic range of 110. In other words, by virtue of aerobic training, the more trained athlete added 10 BPM to her aerobic range.

      This means that a high resting heart rate doesn’t mean that your MAF heart rate should be correspondingly higher, but rather that you have more work to do in order to either bring your RHR down or increase your speed at your MAF heart rate (or both).

      • Thank you for this reply. I think what puzzles me is that my low resting heart rate tells me (perhaps erroneously) that I’m pretty fit, yet the pace at which I have to run (>11 min./mile) is WAY slower than the target pace I need at my age to qualify for Boston Marathon (9 min./mile). That suggests I am way less fit than I infer from my heart rate. I infer from reading at this site that even very fit athletes can have underdeveloped aerobic capacity, so perhaps that’s all that’s going on.

        However, I see that on June 30, you replied to Mike’s question that metabolic, not chronological age should be used in determining MAF. But you didn’t reply to Sean Rodger’s follow-up question about how to determine metabolic age. I went to this site and determined that my fitness level (44 years) is 20 years less than my chronological age. So is 44 equivalent to my metabolic age (or at least a reasonable approximation?). If so, that suggests I need to add 20 BPM to my MAF heart rate, at which point my training pace would come much closer to my target marathon time; this would make much more intuitive sense to me.

        I’ve been training for this marathon since last November, but only been using the heart monitor/MAF target for the last 10 days. Obviously I could keep training at the much slower pace to see if my time improves, but I’d hate to discover too late that I’d inadvertently de-conditioned myself by running too slowly etc. But I’m also mindful from the many comments here that many athletes “feel” as if their MAF-driven training pace is too slow, when in fact they’ve been training too long at too fast a pace.

        • I actually should go back and revise my answer to Mike (as it’s not specific enough). Use your chronological age, unless you get a full array of clinical tests to determine your metabolic age. But let me answer this way: your MAF pace is NOT your marathon race pace. Your MAF pace is strictly for developing your aerobic system. Racing is a different thing altogether. Usually, you want to be racing a marathon some 10-15 BPM above your MAF heart rate.

          You can’t really de-condition yourself by running too slowly: training intensity is a function of heart rate, not speed. If, for example, the temperature where you live suddenly rose to 104 Fahrenheit, you’d be doing a brisk walk and you’d probably already be at your MAF heart rate. Even though you’re going at a lower speed, the metabolic cost of going at that speed in those conditions is actually the same as going at a higher speed in milder weather. If your heart rate remains the same, so does the training effect.

          Also, it’s all but impossible to lose conditioning for a marathon (of all races) by training for it at your MAF pace. Over 99% of the fuel that you use for a marathon should be coming from the aerobic system, and training at your MAF pace is the best way to make sure that happens. By running faster, even though you feel you’re training more, that’s not really what’s happening, particularly when it’s a marathon you’re training for. By going beyond your aerobic threshold (beyond MAF pace) you’re going to be predominantly developing the anaerobic system (but neglecting the aerobic one). In other words, you’ll be training a lot – but you’ll be training the wrong engine. Even though your speed will rise quickly, your endurance (which is a function of the aerobic system and the burning of fats) won’t.

          • This is an EXTREMELY helpful reply. I’m realizing that at least part of what’s going on relates to the fact that I’m training in NC in temps that typically are in high 70’s or 80’s. I have definitely noticed that when I run early in AM when it’s relatively cooler, I’m able to run at a much faster pace without exceeding MAF heart rate. So I will stick with MAF training and see where that leads. Thanks so much for your help.

  • […] What intrigued me most about his training approach was the emphasis on heart-rate monitoring, which I am a big fan of already, as you can tell from my workouts above. However, rather than having a variety of heart training workouts like I show above, Dr. Maffetone recommends a simple training method known as the 180 formula. […]

  • Mike says:

    For power athletes, is the MAF base building process more difficult to adapt to, given that the anaerobic fibers are more developed? I alpine ski race and weight training and intervals are a good portion of training for that, and I’ve neglected base. I find on the bike, gentle grades stimulate leg muscle tension, which puts me over MAF. Are the FT fibers responding anaerobically at that point? Or aerobically? I can ride comfortably at MAF with spurts of +10-15 on upgrades then back to MAF over 2+ hours with no problems. I’m 8 weeks into MAF base, does it work for everyone… eventually?

    • Mike:

      Yes to both questions, except that I would rephrase and say that the MAF process isn’t more difficult to adapt to, but rather that it takes longer, and not because anaerobic fibers are more developed, but because less time has been given to aerobic fibers. And strictly (but very importantly) speaking, the aerobic system isn’t just the aerobic fibers. The aerobic system is the combination of fibers, sweating system, water management system (blood volume regulation), capillary networks, diaphragm and deep abdominal muscles, alveoli, mucous membranes, sinuses, etc. The reason I cite all of these components is to say that by training the aerobic system, you are rounding out the body and the body’s capabilities to a much higher degree than a lot of people think.

      (What I mean to say is that you’re getting much more bang for you buck than developing fibers).

      There are a couple of issues with your approach. One of the points of MAF training is to reduce the generation of lactate as much as possible, in order to reduce the amount of wear and tear on the body, and to develop the aerobic system as much as possible. The more your training looks like intervals (alternations of aerobic and anaerobic), the more you’ll be training your capability to recover from the anaerobic workload, rather than developing the rest of the aerobic infrastructure. Insofar as you want to develop your aerobic base, stay away from that. What’s the golden rule for base building? Zero anaerobic.

      MAF base building works great for a lot of people. There’s been studies on cross-country athletes: when they reduce their overall anaerobic training volume from 35% to 20%, race performance increases. Keep in mind that these are power athletes. The same thing happened to the Dutch Olympic speed skating team: they reduced their anaerobic workload, and they raked in the medals. Even for power athletes, a high volume of anaerobic training just doesn’t do what we’d like to think it does.

      • Mike says:

        Thank you for the added detail, just what I needed.

        • You’re welcome. MAF is about principles more than anything else. Once you really catch on to what those principles do (and why they’re there), you can apply them to just about anything.

          Everything said, anaerobic training is definitely important, and it definitely has its place, just not at all in base building, and not in the volume we think it does.

  • […] and eventually realized my HR was way too high on easy days.) I’ve been basing my aerobic HR on Dr. Phil Maffetone’s formula of 180 minus your age (ends up being 150-155bpm for me). It’s been pretty eye opening. On my […]

  • Andrew says:

    My max would be about 145, but it’s too difficult to run slowly enough to keep it that low. The lowest I can get while running is about 160.

    I would probably need to walk instead (but then it would drop to almost a resting rate! And walking doesn’t feel like it’s doing a whole lot).

  • Lee says:

    I’ve finally started in on MAF heart rate training. I was going to three years ago but hooked up with a Bowerman disciple as coach. That training may have had something to do with my declining performance in 2013 working towards a second marathon that year, fatigue, pneumonia, other health problems surfacing, etc. Finally close to normal and weird issues off and on for decades are all being sorted now by a guy who’s not only an MD but does osteopathic and Chinese medicine. You know, an MD that understands nutrition, cracks your back and sticks pins in you in a single visit. (What, all don’t know that stuff?! They should.)

    Anyway, I’m not an Apple cultist. I’m an Android atheist. Any hope for salvation with an Android app? I mean, geez, we do make up half of the world’s smartphone users.


    • Lee:

      We here at MAF are disciples of The Church of Jobs.

      Just kidding. There’s been a lot of requests for an android app, and we’ll get to it as soon as we’re big enough.

      Sorry you’ve had training setbacks. Glad you’re with us now.

  • Lanny says:

    Hi there

    I am really looking forward to giving the Maffetone Method a try. But I do have some reservations! I am what is considered a high beater, with a current max HR of 202. If I use some of the other current methods to calculate my HR zones I find it to be consistent with the training and effort. Now, if I apply the Maffetone Method (I am 52) I get a crazy low number for my zone. I was wondering if there is any consideration for people that have a higher heart rate?

    • Lanny:

      Max heart rate is a measure of cardiovascular power. It doesn’t say a lot about aerobic function. A lot of people want to put these two measures together, but they’re actually pretty unrelated.

      • Gail says:

        I also have a very high heart rate, The maximum I’ve reach on my chest strap heart rate monitor is 208 when most formulas for Max HR say that my max should be around 186 (I’m 34). My heart rate reaches 140’s on a walk. Using the 180 formula (I have Asthma and take regular medication) my MAF is 131. It just seems unlikely that I would have any gains from this when my heart rate on a very easy run is around 176. I expected to slow down but that seems like an awful lot. Is there any instance where the 180 method is scaled?

        • Gail:

          Yes, but not in these cases. MAX Heart rate and MAF heart rate measure two different things, as I said before: MAX heart rate is a cardiovascular measure—how fast your heart can pump without blowing up. MAF heart rate is a metabolic measure—how much power output you can manage before your metabolism has to utilize anaerobic channels. The likeliest reason that it seems very easy is because your aerobic system is very undeveloped.

          Also, note that perceived exertion (what you describe as “very easy”) is largely unrelated to exercise intensity. For example, the reason why cyclists perceive that their MAF heart rate is very difficult to get to, while runners (typically) perceive the opposite, is because runners use a lot more muscle groups for stability. Cyclists are supported on 5 different points at any given time (handlebars, pedals, and seat), while runners have only one. This means that the runner’s metabolism has to be feeding all of these muscle groups, while the cyclist’s metabolism can put a lot more power into fewer muscle groups. So, even though both metabolisms are going at the same rate, the cyclist’s metabolism is focused on feeding a few muscles, while the runner’s metabolism is spread relatively thin.

          Perceived exertion has to do with the brain. Specifically, perceived exertion has to do with peak neurological function—the amount of “voltage,” so to speak, that is being sent down the spinal cord to any given muscle. The cyclist’s peak neurological function is greater than the runner’s, for any given level of metabolic output. And that’s why running at 176 BPM seems “easy” to you, while it would probably seem damn near impossible if you get on the bike.

  • Al Ciampa says:


    I train Airmen as part of my job as health promotions director for the Air Force. I am whole-heartedly sold into this type of training, and am trying to do it with different modalities. One in particular is using KB swing intervals to spike the HR to their aerobic max, then rest long enough to let HR drop sufficiently so that the next set does not exceed their aerobic max. It works very well, but I do not have enough data yet to show how it effects their MAF test.

    I do have some questions:
    – as has been mentioned here, a formula is just that; if you know your HR @ lactate threshold, is there a recommended aerobic HR max, based on these values? 20 BPM less, or something?
    – it seems like this method prefers not only to avoid anaerobic glycolysis, but also aerobic glycolysis. Is there a blood lactate value that lines up with this “lower threshold”?
    – lastly, as has been mentioned, so many elements affect HR other than the activity. Is there a reason that, once you have learned PER and ventilation rate as related to HR during exercise, that you can’t use a combination of the three to drive your session? Some days, my HR is just out of control (no extra wind, hills, external elements, etc) but my ventilation rate and PER is the same as any other run. Thoughts?

    Lydiard had a lot of success using nasal breathing/talk test while running. Same thing, or no? I know that when I run on an indoor track in the a/c, my pace is much quicker for much longer than when I run outside on the same day in the heat and direct sunlight. Are we to assume that these elements (heat/sunlight) are kicking up lactate, and so H+, production (avoiding which is one of the points of running slower), or should we be able to subtract the difference out, ie. run to a higher HR?

    You mentioned that HR is a measure for overall, systemic stress… if the stress is not contributing to H+ production, should it “count”. Or does all stress increase acidity?

    I hope that my questions make some sense, and I thank you in advance for your time.


    • Al:

      Thanks for your comment. Excellent questions.

      Even though a formula is “just that,” trying to ascertain where the aerobic threshold is for a variety of different age groups works much better with the 180-Formula than with just about any other method, which is why we go by the 180-Formula instead of any other of the many suggested methods on various of these comment threads.

      One of the big problems is that the amount of aerobic function fluctuates due to stress. In other words, if you hit a certain exercise intensity (the anaerobic threshold) you know that your lactate levels are climbing. However, if you reduce that exercise intensity, you have no guarantee that your aerobic function is substantial enough that your lactate levels begin to drop (that you are developing the aerobic system instead of the anaerobic one). The only way to guarantee that is to hit a certain heart rate (or to measure exercise intensity in function of heart rate).

      I believe that a lot of the suggestions of alternate methods made in these comment threads is almost a form of negotiation with the inevitable: we want to have the opportunity to train at a high intensity because we still believe that training at a high intensity is where the magic happens. However, there’s been studies, and examples, that show that the diminishing returns of high intensity exercise start at a 20% of training volume, rather than the 50% or 60% that we’d like.

      Furthermore, it has been shown that a reduction in anaerobic training volume from 35% to 20% (while keeping total training volume intact) actually increased race performance in track and field athletes. Note that these are power athletes, not endurance athletes. Similarly, the Dutch speed skating team had massive successes at the 2014 Olympics due to a reduction in the overall percentage of anaerobic work from 40% to 30%: the most substantive change made to their training was anaerobic/aerobic ratio.

      Simply stated, there are many, many advantages to training a lot slower than we’d like. Negotiating and inventing our way towards justifying a higher training intensity just isn’t going to give us the advantages we think it will.

      To answer your question about aerobic glycolysis, it’s impossible to eliminate it. Glucose goes through glycolysis, period. It must, in order to get to the citric acid cycle. Our options are for it to transform into lactate, or into pyruvate.

      If heart rate is out of control, then it means that your stress levels are putting it out of control. If heart rate is tough to bring down, that means that your body is having a tough time functioning aerobically rather than anaerobically. There is a 1:1 correspondence between heart rate and ratio of aerobic/anaerobic function.

      In regards to your question about Lydiard. Increases in heart rate are tied to increases in anaerobic function because of the stress response. The stress response is designed to make the animal survive: run fast, fight hard. In order to do this, it recruits the short-term, high-octane fuel supply: the ATP-PC system and the anaerobic system. And it gets the heart to pump blood as hard as possible, to bring blood to the muscles. This three-way connection runs so deep in our physiology, and is so hardwired into every living being, that it is literally impossible to divorce an increase in stress from an increase in anaerobic function, or from an increase in heart rate.

      If you increase any one of the three, the other two will follow.

      In survival terms, it makes all of the sense in the world for the connection between stress, heart rate, and anaerobic function to be as tightly wired as possible, and to have the capacity to overload, bypass, and overcome literally every other last bit of the organism’s wiring. If it doesn’t have that capability, that organism may be destroyed in the next 30 seconds.

      This ties into your question about lactate production. It’s not that the sun is kicking up lactate production directly. It is that using the sweating system increases the energy demands of the body. Heart rate rises in order to increase blood supply, and anaerobic channels are recruited to run the sweating system at a high rate.

      Until the aerobic system develops further to meet those demands (and heart rate lowers in function of that), you’ll be using the anaerobic system.

      The depth of the stress-anaerobic connection accounts for why chronic stress leads to chronic illness: if there is a constant stress response, there is a constant recruitment of the anaerobic system (and a high resting heart rate, hypertension, etc.). Lactate is being produced, and not being properly expelled, and the body is acidifying as a result of that.

      There is no way around this. We’ve been trying to find it, and trying to negotiate with it, and as a result so so many of our athletes remain unhealthy and overtrained.

  • JeffM says:

    I’m really glad that I found this site as I have just started using the 180 Method and my experience so far mimics paid day and others. I’m currently training for a marathon in October. My plan was to use the 180 Method exclusively for the next 6 weeks and then add in 20% anaerobic work for the final 6 weeks. However, a concern has cropped up for me based on some answers to other people’s comments. It looks like you recommend a maximum of 5 75-90 minute sessions per week. If I try to use a typical marathon training plan I will exceed that to get in the recommended mileage. Is that acceptable or do you have a recommendation on altering the marathon training plan for use with the 180 Method?

    • Jeff:

      So, those 75-90 minute sessions include 15 minutes of warm-up 20 BPM below MAF, and 15 minutes of cooldown at the same MAF. So you’re really getting 45-60 minutes of MAF training (which isn’t very intense). So you should be fine. That said, your body is the best judge. Listen to your body. Tired that day? Feeling like you shouldn’t get off the couch? Take another day of rest. Remember: adaptation happens in recovery, not in training. You’re not “losing” anything in being generous with your recovery.

      Another thing to consider is that the marathon is 99% aerobic. This means that you don’t really need any anaerobic training to run the marathon, except for your ability to maintain a good level of power in your legs. So do this: for those last 6 weeks, do a little bit of power training on a track (but don’t focus on it being anaerobic). Do 7-second intervals where you get up to your maximal speed. As soon as you hit that speed, taper off and jog around the rest of the track. You can do that for 1/2 hour 2 times a week, with a good warm-up and cool-down before that. Do your regular MAF training the other 5 or 6 days.

      “Power” isn’t in the muscles. It’s in the brain’s capability to send more voltage down the nerves into those muscles. (Of course, in order for them to accomodate that voltage, they have to grow). But with this exercise, you’re training the brain’s capability. That’s what you want, especially for an endurance event like the marathon. If you train the brain, the muscles will follow. And the benefit is that your muscles won’t be NEARLY as exhausted afterward.

      Finally, TAPER TAPER TAPER TAPER. I can’t stress this enough. Take a good week to really tone down the training. Let your body recover. It will need its strength for the marathon. I usually do 80-70-60-50-40-20-10 (in terms of percentages of usual training volume). In this period, your body will be insisting that you train: it’s got energy to spare. You don’t need to train. Nothing that you do a week before the marathon will improve your race time. At that point, it’s time to let your body rest.

      • Rudy Hassall says:

        Hello Ivan,
        For clarification, when “I usually do 80-70-60-50-40-20-10 (in terms of percentages of usual training volume).” is stated.
        Is that meaning start to taper 7 weeks out from the event?
        To mean if 10% is the week of the event, then 3 weeks prior to the event we should on train at 50% of our normal training volume?
        Also, for a marathon or half-marathon or OCRs, would you recommend implementing HIIT?
        Thank you in advance.

        • Hi Rudy, I was referring to the final week. It really depends on the event, sometimes I’ll taper two weeks or more, depending.

          I would recommend some HIIT towards the end, keeping it to a maximum of 2 days a week and ensuring that you get enough rest to fully recover (and be fully rested going into the race) while also continuing to have a relatively long run every week so that you don’t adapt away from the endurance required.

  • JeffM says:

    Thank you for your response. I ran 4:02 in my first marathon earlier this year. I’m hoping to break the 4 hour barrier in October. Right now my 180 method runs are in the 13-14 minute per mile range. I’m optimistic that will improve before October but probably not into the 9 minute per mile pace that I will need to break 4 hours so I will still be mostly using my anaerobic system for this marathon unless I am misunderstanding how this works. Of course, that wouldn’t surprise me since this is all new to me.

    • Jeff:

      I understand what you’re saying. The MAF heart rate isn’t your marathon race pace. Your marathon pace should be 10-15 BPM above MAF. That said, you need to develop aerobic power for the marathon, not anaerobic power. If you go more than 10-15 BPM above MAF, you’ll end up hitting the wall. That’s what the wall is: premature depletion of stored liver and muscle glycogen. What I mean by this is to say that you can’t use more than a little of your anaerobic system (10-15 BPM) anyway, since your target pace will plummet as soon as your glycogen gets depleted. The less trained your aerobic system is, the faster your glycogen will be depleted, and the faster you’ll hit the wall.

      (You don’t really need classical anaerobic training to race 10-15 BPM above MAF. All you need is a few short runs at that pace, just to get used to the feel of it). But to train for a marathon as a beginner, every athletic activity that you would classify as “training” should be done at MAF pace.

      In order to reach your target marathon pace, you really don’t have any choice in the matter but to continue developing the aerobic system, and to ensure that’s primarily the one you’re using during the marathon. When you’re able to hit that target pace and maintain it throughout the course of a marathon will be due to the development of the aerobic system, not the anaerobic one.

      Only at the advanced level, when you’re trying to break the 3 hour mark, do you really need to juggle anaerobic development with aerobic development. The aerobic system should really be the one responsible for taking 90% of people down to the 7 minute mile mark, and 9% of people down to the 6 minute mile mark.

  • Stacey says:

    I have had an Active Metabolic Assessment and had my HR Zones identified. I”m a female and 50 yrs old. My resting HR is about 46 and my Max is 206. I try to keep my runs in Zone 3 which for me would be below 175. The beginning of Zone 1 for me is 150 but your calculation has my running at 135. My HR climbs fast and runs high but it also recovers very quickly. Do you think that 135 is still the correct number for me to try to hold? I’m a Group Fitness Instructor so I have spent many many years training in a very high HR Zone with lots of Interval Training. Have I taught my HR to run that high?

    • Stacey:

      The MAF heart rate was the one that Mark Allen needed to hold, even after he had been an elite triathlete for a long period of time. What I mean to say is that despite his cardiovascular power, Mark Allen had a pretty compromised aerobic system. The maximum aerobic heart rate (MAF) is a measure of aerobic function, rather than cardiovascular function (which MAX is a measure of). Judging by your resting heart rate, you are either in the late stages of parasympathetic overtraining (unlikely), or, as your history suggests, quite aerobically developed.

      You may not need to train exclusively at the MAF pace, since there is a high likelihood that your aerobic base is far more developed than most. That said, if you DO want to train the aerobic system at the exclusion of the anaerobic one (base-building), the MAF heart rate is the one that you should be sticking to. That is pretty much certain across the board. We at MAF stress training at an aerobic heart rate so much because such an overwhelmingly large part of the population is aerobically underdeveloped. But let me reiterate: you may not be one of those people, which is a reasonable conclusion given the history and heart rate metrics you present.

      That said, if you do find yourself flirting with overtraining in the future, training near-100% of your volume at the MAF heart rate is the way to go.

  • JeffM says:

    Perfect response.
    Thank you,

  • Sebastian says:


    Thank’s a lot your input. I find your messages very useful even though I’ve read both of the Phil’s books.


  • Kerry says:

    I find it immensely enjoyable to trail run (jog, really) at heart rates below MAF, and often only get in to my MAF zone of 125-135 on hills. I do some of my runs and bikes in the MAF zone, and very little over. I rarely race. When I do, I’m usually competitive in my age group.

    Am I slowing my aerobic development by running much of my volume below my MAF zone, often around 118bpm? My MAF pace is improving, but very slowly.

    Any thoughts?

  • Nicole Chauvet says:

    Hi Ivan,

    I’m glad I found these comments! I have a few questions. I’m 45, so 180-45=135. I’ve been trying to do this for three months now, the first month I struggled with slowing down and following the MAF test correctly and I had some serious HR monitor strap issues. I have a Garmin watch and HR strap that basically, sucks. I switched over to Polar for the strap and found I was probably running too high for the first month. Now I’m fairly stable in HR. I too am struggling with having my running pace drop from 9-10 pace to initially 14-15 minute pace, if I was running at all! I am still in the jog/walk mode for most of my training but I’m now in the 13-14 minute pace. Will there reach a point when I can actually run again!? This has been a Huge challenge for me because I was one that almost never walked when I went running. I would say I’m still walking 50-60% of my runs with that number increasing as the miles/time goes add up. Is that normal? Finally, it was just now that I read that I should be running about 5 times a week. This is considered normal and beneficial for the speed of adaption? I use a Heart Rate Variability app to judge my fitness level everyday and if I should train. It was great reading about adding jumping rope! I had added that instinctively a month ago and I make sure to keep my HR under my max. But that being said, I would be happy to add in a run instead of jumping rope twice a week. Also, I saw on the app to double up on workouts on one day. Would that be a good idea while establishing the aerobic base or later?

    • Nicole:

      All joking aside, the real answers to all of your questions is “it depends.” Generally, people run for the entirety of their runs about 2 months after they started, supposing that they are walking more than 50% at the beginning. But it’s very hard to say, as people’s biomechanical and physiological circumstances are very different. Generally 1h-1h30min 5 times per week is the best for exercise adaptation. The reason that doubling up on workouts works so well is not that you do double the amount of exercise, but rather that your body gets reminded that it needs to adapt twice a day instead of one. In other words, the exact same training volume split in the morning and the afternoon would yield greater results than if it is put together. (Also, think about the fact that you have the opportunity to recover between periods of exercise). Is that a good idea as you’re developing the aerobic base? Sure.

  • Rudy says:

    Like Nicole I am mostly walking during my workouts.

    I am 46 yrs of age
    With the formula my MAHR is 134 bpm
    My resting heart rate is 72 (want to lower this number)
    I use a Garmin FR610 and Fenix3 with a heart rate monitor strap.
    I follow the (FIRST) program, with the “3 plus 2” program for running
    I also throw in some odd trainings, as I like to run in OCRs

    At times, there are long/slow runs that I may do on the weekends for duration at a slow pace, anywhere from 1 to 3 hrs to increase my endurance.

    My recent 2hr run was this:
    15:33 min/mi Avg Pace
    14:24 min/mi Avg Moving Pace
    953 ft elevation gain
    151 bpm Average HR
    168 bpm Max HR

    It is all I can do to keep my heart rate 146 – 155 bpm, as this is what I have programmed in the watch from Garmin Connect.

    Are there any recommended MAHR workouts to lower my resting heart rate and allow me to run during my runs, instead of walking them?

    Thank you in advance!

    • Rudy:

      Not really. There is no real way to develop the aerobic system at maximum speed except to exercise at the MAF heart rate. The problem you’re experiencing (wanting to be able to run faster) really begins with the fitness community’s overemphasis on high-intensity training. Simply speaking, most of us never developed the aerobic system. Your speed at the MAF heart rate accurately portrays the status of your aerobic system. Really the only thing you can do is to acknowledge where your aerobic system is at, and go from there.

  • Matt says:

    I can’t wait for the new app. In the mean time I have a polar h7 heart rate monitor. I’m looking for an iPhone app that will give me audio feed back when I’m above a specified heart rate so I don’t have to check my phone (which lives on my shoulder during the run)

    • Rudy says:

      Thank you for the detailed response.

      As the (FIRST) program, with the “3 plus 2″ program for running, is high-intensity training, as you stated.

      Are there any training programs that leverage the 180 Formula?

      Thank you,

      • Rudy:

        Let me begin to answer that by saying that we’re about to start training people in-house. That said, there are no programs as such that leverage the 180-Formula. The reason is that the body is continually changing and adapting to an innumerable amount and variety of stressors, and what worked a week ago may not work now. Giving you a six-month program (or whatever) really means that we are betting that you are a person of type X exposed to stressors of type Y. That is irresponsible.

        However, we do use the MAF test as a diagnostic tool: if your MAF speed (at the heart rate given by the 180-Formula) has been rising steadily for 3-6 months, it’s time to incorporate sports-specific strength and power training (80% of your total training should still be MAF, 10% of your training should be between MAF and your lactate threshold, and 10% should be beyond). During this time, do MAF tests every week to see if your speed begins to plateau or drop. If it does, scale back on your strength training for a week or two until your speed starts rising again, and return with 84-8-8% instead of 80-10-10, etc. That way, you’ll know for sure whether you are training correctly, and you’ll have much more freedom to invent a training program than you ever could if we gave one to you.

        (Our coaching model is designed to mentor people in the understanding of these principles, and how to modify their own workout routines so that they can ultimately achieve athletic independence).

        I hope this helps. And please shoot back with more general or specific questions. I’m always happy to answer.

  • Gunter Woytowitz says:

    Hello Ivan,
    I’m 50 years old and struggling with the “I think the MAF heart rate is too low” just like everyone else.
    I won’t try convince you to allow me to add 5,10, please maybe please 15 beats to my 130 number because I’m a special super fit nice guy 🙂
    I’m on board and will keep training low and slow for the NYC marathon in November.
    However, I would like to know if there are any theories as to why our aerobic capacity has a linear decline with age?
    My engineering brain would be happier thinking about these theories during my current sluggish 11 minute pace 🙂

    • Gunter:

      It’s actually quite non-linear. I can’t cite you any sources off the top of my head, but to give you an idea, aerobic capacity peaks at around 45, and then starts to slowly decline. By the time that you’re 65 or 70, you’ll have about as much aerobic capacity of yourself at 18. However, there are quite a few old Tarahumara runners whose sheer running skill would beg to differ.

      That would be an interesting article, though. You may see it up on the site before long.

      • Gunter Woytowitz says:

        Hello Ivan,
        That would be an interesting article and look forward to reading it!! but… it was not exactly what I meant. To be more precise, I was referring to the linear component of age in the MAF 180-age heart rate formula. Also reading about the Tarahumara in Born to Run and that endurance can last well into old age, it seems counter intuitive that the the MAF target heart rate decreases linearly with age, but the aerobic capacity is non-linear as you have described. Just curious if there is some “logical” theory/explanation for how/why the MAF formula works.

        • Gunter:

          I see. About the Tarahumara, what you’d probably find is that the elders’ MAF heart rates are actually as low as you would expect with the 180-Formula. Their aerobic power relative to heart rate should be incredible. (That’s why people can run 9 minute miles at MAF on day 1 and 7 minute miles on day 180). The Tarahumara elders are examples of what you get when you’re at day 18,250 of running aerobic miles. These guys just have huge aerobic bases that they’ve developed throughout a lifetime of constant running, so their heart doesn’t need to go up very far. But what we would expect is that if their heart does get beyond their expected MAF zone, they would start using anaerobic channels just like anyone else.

          (Of course, with an aerobic base that powerful, the elders wouldn’t really have a problem with a bit of anaerobic work).

          But MAF heart rate does not decrease linearly. For simplicity’s sake, we tell people over 65 to add 10 BPM to their heart rate if they’re healthy. On average, the fact that aerobic function does NOT decrease linearly with age (while cardiovascular power does) starts showing at around 60-65 years of age.

  • Thomas says:

    Hi,love the site,i am new to the 180 formula and i carried out a MAF test afew days ago,i am 34 years old and i have being off training for the last 8 months with fatigue so this gave me 180-34-10 = 136bpm,when i did my first run using this i did 15 mins walk warm up,30 mins run at 136bpm,15 mins walk cool down but what i found was about 1 min into my cool down my heart rate shot up to 156bpm,as i am new to heart rate training i didnt know if this was normal

    • Thomas:

      How long did it stay like that?

      • Thomas says:

        Hi,it stayed like that for for about 1 min,i stopped walking for a few mins and my heart rate went down,after that it was fine,i have gone on another run since and this did not happen,everything went perfectly,it was my 1st time using the heart rate monitor so maybe something went wrong,i will keep an eye on it,thank you for your reply

  • Buzz says:

    Hi Ivan

    Thanks for all your answers to questions above, I have learnt a lot.

    I am very keen to get your advice regarding my situation. I’m a 40 yr old male who has run my first 3 marathons over the past year – all at around the 4 hour mark.

    I have been running for about 4 years but have only upped the km’s over the last 18 months. I have been injury free over the entire period and don’t take any medications. My MAF number is therefore 140.

    My question is this: My HR seems to consistently be 10 to 20 beats higher than anyone I run with. My max HR is around 200bpm and when running at a very comfortable, conversational pace my HR is around 155-160. I can very comfortably run at this pace for 25-28km (15-17 miles) while chatting throughout. My resting HR is 70-80bpm.

    It is possible due to my naturally higher HR that my MAF number is actually higher than 140bpm?

    Thanking you in advance.

    • Buzz:

      If I were you, I would refrain from calling your higher heart rate “natural” until you’ve done a battery of clinical tests to ensure that. Self-diagnosing in that way may be preventing you from realizing that you may (or indeed, may not be) slowly wearing down your physiology until you get overtrained “out of the blue” a few years down the line.

      Your MAF number could be higher than 140. But training conservatively has many benefits. Before you make a decision to run at a higher heart rate, I recommend that you listen to this exchange between Richard Diaz and Phil Maffetone on the topic of submaximal training. Simply stated, running at a low intensity has many benefits, and we lose those benefits (and don’t gain others) by reducing the amount of true low-intensity training that we do.

      Don’t get me wrong here: you could be completely right about your body. What I’m trying to say is that until that battery of clinical tests have corroborated your hunch, you don’t really know if you are. I would stick with the 180-Formula. The phenomenon of training juuust a little too hard for juust too long is what has put legendary runners like Anton Krupicka and Geoff Roes out of competitive form for good. Don’t make that same mistake.

  • Adrienne says:

    Hi guys, I’m reading and listening to podcasts about the Maffetone method for the first time. I had a question that I’m guessing is probably a common one: I want to use this method, but in the 90 degree heat and all the humidity right now, I find it really difficult to keep my heart rate under 142 during a long effort. Today I tried deep breathing and slowing down without stopping during my run and was unable to keep under it. Is there any allowance given for training on hot days?

    • Adrienne:

      Absolutely not. The reason your heart rate spikes when it’s hot is that the body has to increase its power output in order to drive the sweating (cooling) system, which may well be the most costly system in the body besides the brain. That heart rate spike is a direct indicator that your aerobic system isn’t powerful enough to drive the cooling system, meaning that your body is using anaerobic energy channels to be able to sweat at the rate it needs to. If you need to walk, walk.

      However, remember this: because the ratio of aerobic-anaerobic function is based on heart rate, so is exercise intensity. So, even if you’re going slower because it’s hotter, at the same heart rate you’re still training the body’s systems at the same intensity. Know that the sweating system and the metabolism are much greater contributors to a higher athletic output than muscles are. By training them, you are expanding your athletic potential much more surely than by running faster.

      • Tom.M says:

        Is there anyway to do hill sprints while following MAF guidelines? Also, I’ve read that doing nothing but LSD training, makes you exactly that, slow. Not unless your name happens to be Ed Whitlock ))..

        I can see this being great for maintaining longterm health and preventing overtraining syndrome. However, what about folks who want to “race” the marathon?

        Does always having to stop jogging just walk to keep your HR down have any effect on development of your leg (running) muscles and on your running economy?

        • Tom:

          Training exclusively at MAF is for building an aerobic base, recovering from an illness, an injury, or overtraining. At any other time, 15-20% of your total training volume should be anaerobic. As long as hill sprints fall into that 20%, that is within MAF guidelines.

          Your “running” muscles are really your metabolism, not your leg muscles, particularly if you’re a distance runner. A very important component of being fast at the marathon is to be able to run that speed without depleting your liver glycogen. Regardless of how powerful your leg muscles get, if your liver glycogen goes, so will your speed.

          Walking more and running less will mean less muscle development. But if you’re having to walk to keep your heart rate at MAF, the problem isn’t your muscles, it’s that your fat (aerobic) metabolism can’t fuel your muscles at the rate at which you’re asking it to, so your body has to rely on your anaerobic system. For the length of the marathon, that is unsustainable. In other words, what’s keeping you slow isn’t your muscular development, but your metabolic development. Once you solve that problem (by developing your fat metabolism), the issue will become one of muscular power. Not before.

  • Fred says:

    Hello, What an interesting site. I surf all the time for inspiration and I’ve found it with the 180 method. Former career soldier, always had to train so as to lead from the front. (With difficulty sometimes). Ran 6 marathons since 2010 and into my last 9 weeks of a 20 week training program for the Berlin in September. I run at a snails pace compared to Paula Radcliffe.. My fastest marathon is 4 : 47 : 58. (Albeit run/walk method because of my RA). I’m now 66 and my aim is to go sub 4:30, (4:29:59) would be just great.(I’m now able to run all my training days because my medication has finally kicked in and my super liners help too). Resting HR 48-50, MHR about 180 at super fast speed at the end of a 5k Park Run. My PB 5k is 26:47 last Saturday morning. My MAF HR is 180-66-10 for Rheumatoid Arthritis in my feet and hands. Should I continue to run at 104 BPM throughout my last 9 week program. My plan calls for some speed work and some Tempo runs. I’m nervous to the point of not testing myself before the Berlin. Clear as mud, I know. Thanks!

    • Fred:

      Keep running at the MAF heart rate. That said, your marathon heart rate should be some 10 BPM above your MAF heart rate. What I would do is run one or two short runs at this pace, just so you know what it feels like. But unless you are trying to bring your speed down from a 3 hour pace, tempo runs and speed work are really not going to help your marathon results. The marathon is an overwhelmingly aerobic event, and the fact that most training plans don’t treat it this way is to the detriment of athletes.

  • Jess says:

    Thanks for all of the helpful information – I’m excited to begin. My concern is that I’ve always had a relatively fast “resting” heart rate and so I had trouble staying below target during a VERY slow walk. I’m 40 years-old but am fairly out of shape and have a complicated medical history so I did 180-40-10 to come up with 130. The problem was that my average heart rate during a 40-minute walk was 135 – I slowed down to a crawl and couldn’t get it to go below 130. I’m assuming that my aerobic base is just that bad, but I’m trying to figure out if I can still expect to see improvement even when I’m technically training over target to start. I hope that question makes sense.

    • Jess:

      You can, but do your best to go under target. Your intuitions about why your resting heart rate (RHR) are high and speed is so slow are likely spot on. In other words, try to get under target as fast as possible. And in terms of whether you can expect improvement, it’s when you’ve hit bottom (or are close to it) that there’s nowhere to go but up. People with a very atrophied aerobic base are people with a great need for aerobic development—and with a body that is desperate to build an aerobic system. If you stick by the principles, and work diligently, you’ll see improvements (first in health, and then in speed) come surprisingly quickly.

  • Shardul says:


    Need to know for a new runner who is trying out MAF , how much is the maximum distance to start with .

    • Shardul:

      Don’t think in terms of distance. Think in terms of time. What I would do is start 1 week with 5 consecutive days of running. Do 15 minutes at MAF heart rate, with 15 minutes of warm-up (20 BPM below MAF) and 15 minutes of cool-down also 20 BPM below. If that works for 5 consecutive days, after the two days of rest, bump it up to 30. Starting with a low training volume and increasing if you can handle it will benefit you a lot more than overreaching at first.

      • peter says:

        Dear Ivan,

        I’m gathering information around warming up & looking around on this site to find it.
        There is very few specific information about this.

        Your reply above seems to be the answer that comes back often on this page.
        However, I also found this:
        “it simply means that you start walking slowly and build up your pace over a 15-minute period” (source:
        To me it is a big difference: walking slow is about 80 to 90 BPM, while MAF-20 = 120BPM.

        It would be great to get some feedback.

        • Hi, Peter

          My comment spells out the minimum increase (20 BPM) to warm up from. A lot of people start off jogging slowly, often putting them at MAF-20 which is fine, and for some others, a slow walk is MAF-20. It all depends on the person. The goal of the warm-up isn’t to adhere to a specific heart rate increase, but rather to get blood circulating throughout the muscles without placing the body in undue stress. This can happen well across a range of heart rates well under MAF.

  • Adam says:

    Hi Ivan,

    Similar to the poster Buzz above, I have a question on the MAF heart rate for my case. For background, I am (like Buzz) also 40 years old, and therefore, according to the 180 formula, my MAF HR is 140. (No deductions or additions apply, but I am a fit, healthy guy).

    I am keen to exercise optimally – that is, develop my aerobic base at the MAF intensity – just before the point where you start to burn too much sugar. Not too fast, not too slow.

    Thing is, I had my maximum heart rate tested under full laboratory conditions. It came out at 200. Now, 140 as a percentage of 200 is (only) 70%. Whereas for most people my age. maximum heart rate would be about 180 (220-40). Thus, for most people my age, their MAF of 140 is 77% of their maximum HR (140/180.

    So my question is: if I exercised at 140 bpm, will this be TOO easy? Like I said, I want to apply Maffetone principles, but I am wondering if I can uplift my MAF heart rate a little? For example, if I increased it to 155, then (in my case), that would be 77% of my maximum heart rate. By Maffetone’s own logic, that would still seem optimal to my mind? That is, I would be working at the same intensity as those my age with the usual maximum heart rate (180).


    • Adam:

      Maximum heart rate is a measure of cardiovascular function, meaning how hard your heart can pump before blowing up. On the other hand, MAF heart rate is a measure of how much stress it takes the entire body to start using anaerobic channels. In other words, MAF is a measure of general stress/metabolic activity, whereas MAX is a measure of the heart’s sheer ability to pump. Although maximum heart rate and MAF heart rate start becoming intertwined when your MAX heart rate is uncommonly low, relative to your age, for most people MAF heart rate and MAX heart rate are unrelated.

      I hope this helps.

  • Bill says:

    I have questions about how to apply this to me at my current stage, but before I do let me tell you about my success with this 14 years ago. I had completed my first marathon but had all the markers of overtraining and came to the conclusion that just because I could run as fast as I was running didn’t mean I should have been running that fast. I started exploring effort-based training, ran into the Maffetone Method, tried it – and was stunned I couldn’t do it at all. I was supposed to keep my heart rate below 120, but couldn’t get it to be there. It would go 80, 90, and then zoom straight to 150! I’d have to stop and walk until the hr came back down again, and those first few days took almost 20 minutes before I could get the hr to finally progress from 90 to 100 to 110 and then 120. It was very frustrating, and slowed me down almost 4 minutes a mile. I didn’t like it, was embarrassed to be running that slowly, but did it anyhow. 3 months later, at that same hr I had regained 3.5 minutes of the speed I had lost. 3 years later I was nationally ranked at some stupidly long runs (more than 100 miles). So, I have evidence that it works.

    However, now I’m coming back after some time not entirely off. I haven’t been sick but had some knee issues that are gone now. My question mostly centers around my just fixing an irregular heart beat – I’m not sure how to treat it in the formula. For now, I am more than willing to pretend it was a major operation to make sure I ease back into it slowly, but I’m wondering at what point the procedure is now so far in the past I don’t have to subtract for it anymore. Can you help me out here? It’s hard to imagine that an hr of 98 is enough to do anything more than walk or shuffle, and I want to run again. .

  • […] in 4 short years. I am intrigued to learn more about her approach to training which is called the Maffetone Method, a heart rate training method developed by Phil Maffetone author of “The Big Book of […]

  • tj says:

    I understand this is really good for long distance training and racing. My question is this a good method of training for someone who runs only 5 and 10 k’s. and only worried about going full tilt.

    • Here’s what I answered to another commenter:

      “The idea of training submaximally (at MAF heart rate) holds for just about any sport. Think about what happens when you develop your power (a.k.a. speed) without increasing heart rate. When you do, you can be much more powerful at a higher heart rate. Why? Because if you have a powerful aerobic system, it takes a lot more lactate production (from anaerobic work) before you reach the anaerobic threshold, which is where lactate starts to accumulate in the bloodstream.”

      In other words, being “only” worried about going full tilt is enough for you to want to train submaximally, since it will benefit your ability to go all out. (Already, when you are running a 5-k, over 90% of your energy use comes from the aerobic system).

  • Carl says:

    Hi there. I have had great results with the 180 formula so far but my wife is struggling. She is new to this kind of training, as was I, but she is not seeing any results with fat burning or in aerobic improvement so far. Her upper threshold is reached with very little effort. She’s been at it now for around a month. By the one month point I had seen significant progress in both categories. Any ideas?

  • […] MAHR? Dr. Phil Maffetone does a good job of explaining how to find your MAHR and why it’s a good idea to train in this […]

  • […] “Being fit doesn’t mean you’re healthy.” He’s also the founder of the 180 Formula, used to improve aerobic fitness via heart rate training rather than constantly doing interval […]

  • Black Elvis says:

    Couple of questions:

    How much total time per day/week should an athlete be putting in at MAF efforts? Are there more gains to be made 2-3 hours of biking per day rather than keeping it to 1 hour sessions? What about 5+ hours in a day? Should we be scheduling rest days every other day or is 5-7 days a week just fine at these low efforts?

    Is it better to warm up, go for an hour, cool down and then come back later in the day for a repeat or to warm up and settle in for two hours?

    Perceived effort: during warm up and cool down (120bpm, MAF of 140) I literally don’t even break a sweat. Long slow breaths. It takes me about 5 minutes to edge up to this, where I hang for 15 minutes (should the first 5 be counted towards the warmup?). Then I pick up speed to 135-140bpm and stay there for an hour: I do (lightly) break a sweat there but the breathing is basically still excessively relaxed…is this normal? Sign that my lungs are that far ahead of the rest of me? Sign my MAF is calculated too low?

    Cool down: another 15 minutes, though it takes 3-5 for my heart rate to recover back down to 120. To do so I’m barely pedaling. Will this recover faster once I’m better trained? And should the 5 coming down be counted toward the 15?

    Just to confirm: occasionally heading out for a fastest mile will damage my progress, right? What about hitting the weights, which is likely also anaerobic?

    • Black Elvis:

      Great questions. Typically, the diminishing returns in training time start after 2 hours of training. In other words, if you do 15 minute warm-ups and 15 minute cool downs, and run at MAF 2 hours in between, you’ll get 90% of the benefit than if you ran 3. Typically, training for 5 consecutive days a week with 2 days of rest in between is best. Remember: more training volume doesn’t beget more adaptation past a certain point. A lot of endurance athletes blew past that point a long time ago. What really matters is the ratio of rest to training.

      The benefit of working out twice a day isn’t so much about increasing volume, but that your nervous system has more reasons to adapt. One 2 hour long event is still “one event” as far as the nervous system is concerned. 2 hour-long events are “2 events.” So, even if you keep your training volume steady, you’ll see lots of improvements if you train twice a day.

      MAF training is NOT—let me reiterate: NOT—about perceived effort. Remember, MAF training is all about remaining at a point where you aren’t producing (let alone accumulating) any lactate in your bloodstream. In other words, you should be very, very relaxed. As you train at MAF and develop your aerobic system, you’ll find that your perceived effort at the same heart rate begins increasing. Don’t worry about it. There are huge health and fitness benefits to training at a LOW intensity. Trying to ramp up the intensity because it “feels too low” won’t get us the benefits that we think it will.

      In 80% of our training volume we should actively be looking for that low intensity.

      Yeah. The 15 minutes before and after should help your heart rate get up there (and back down) naturally. It’s so that the heart rate doesn’t spike or drop. But you don’t need to be going at that heart rate for the full 15.

      Occasionally heading out for that fastest mile, not really. However, it might slow down your progress a little. How much is relative to how much anaerobic work you do. If you do sprints to “stretch your legs,” you know, just to feel the wind blow your hair back, that’s perfectly fine. But as soon as it turns into anything you’d describe as “training,” you’re probably hurting your aerobic base.

      For example, even when I’m base building, if my legs get stiff I’ll do a quick 10-meter sprint, or zigzag down the sidewalk for a few meters. Also, what you can do is, every week or so, do 15 minutes of intervals where you get to your maximum speed and immediately come back down to a warm-up heart rate (20-25 BPM below MAF). If you can only do 1 interval the whole 15 minutes, that’s all you get.

      The only situation where I would say absolutely no anaerobic work ever is if you’re trying to recover from overtraining.

      If you hit the weights at or below your MAF heart rate, you’re doing aerobic training.

  • mehmet says:

    Hello there,

    I am 33 years old. I have been exercising (run,bike,row,some weights) for a couple months, mostly aerobic but not fully compatible. My resting heart rate is 56bpm. Max heart rate I have measured with my heart rate monitor is 209bpm (I think there still may be extra 3-5bpm). Is 180-formula still applicable for me? What modification(s) should I make in 180-formula? Thanks…

    • Mehmet:

      Thanks for your comment. Remember that your MAX HR is a measure of how hard your heart can pump. Your MAF heart rate is a metabolic measure: how much power your metabolism can put out before you have to switch from the aerobic to the anaerobic system. In other words, these two measures are unrelated unless you have an uncommonly low max heart rate. You can have an extremely powerful heart but a very weak aerobic system.

      Don’t modify the 180-Formula unless you have run a battery of medical tests looking at the aerobic threshold (the onset of lactate production), NOT the anaerobic threshold (the onset of blood lactate accumulation).

  • Stu Duffy says:

    I have started following the 180-formula, having also changed my diet after completing the 2 week test. I am loving running to a heart rate – keeping training super relaxed. I have been running for many years and have completed many marathons, but at the moment I feel a bit like Neo in the Matrix – I feel like I’m only now finding out the truth about running. It’s very exciting and I can’t wait to feel the benefits.

  • Phillip says:

    Hi. This just a quick overview that I have done in the passed 5 months since I descovered the 180 formula. I am a keen cyclist I have been racing criterium races for the last 7 years. Each year in the off season I train differently to get some improvement for the following season. This year I have done all my training at the 180 formula. I am 53 so my max aerobic HR is 132. My test is on rollers in my shed on a 50/12 tooth after a 15 min warm up I set 30 min for the test and see how far I would travel in that 15 min. The first test 5 months ago I travelled 20.2km I did my last test 3 weeks ago and now I travelled 22.8 km. this is a great improvement. I have 1-1/2 months to go before the criterium season starts again. I am now only doing one anaerobic training session a week. I am looking forward to the racing coming up. Thanks for the formula.

  • Lila Burnett says:

    I have been using this method for close to a year. It is getting harder and harder to get my heart rate up to my MAF HR. So what used to feel like relaxed, low intensity exercise now feels like really hard work — at the same heart rate. I’m assuming this is progress but it feels much less enjoyable. Any suggestions?

    • Lila:

      It’s because you’re doing a greater volume of work at the same heart rate (assuming that your speed is increasing). What that means is that you’re getting closer to your aerobic physiological limit. That’s good. As long as your MAF tests show improvement, it’s time to incorporate a little bit of anaerobic work.

  • Jim says:

    I’m 76 and been running for 40 years steadily 4-7 days/week. RHR 48 bpm, I’ve always had trouble staying below my 180-age+ heart rate. My solution is to plan to run/walk from the outset. I have a dual timer from galloway that i set for a 30sec walk and a 1.5-2 min run segment. These are nominal settings which I adjust to keep my average HR at or below my 114 bpm limit. (My HR ranges from a low of 100 to a high of 118) I just started this routine a couple of week ago and so far it enables me to keep my average HR under control and I can do a 4-6mi run with no problem.
    My question is this cyclic HR training with the mean HR at the correct limit qualify for aerobic training the Maffetone way?
    Great blog lots of good ideas
    Jim Stanton

    • Jim:

      Generally speaking, try to keep all of your heart rate at or under your MAF heart rate. For example, my MAF heart rate is 149. In a typical run, my average heart rate will be 144. The reason being that, if I would run for 20 minutes at 169 BPM and 20 minutes at 129 BPM, my heart rate would still average out at 149 BPM. But I’m not really doing aerobic base training. I’m doing intervals.

      So, although a high of 118 isn’t bad, I’d still try to get it under MAF.

  • Maurine Lee says:

    I’ve been training using the MAF method since April, 2015. While I am seeing some improvements in my monthly MAF tests, it still seems extremely slow with the improvements. I did battle foot injuries for three years prior to getting back into consistent training. I’m wondering if I should try applying the slower maximum (I currently use 126) but after 4+ months of trying to run slower than 15 minute miles most of the time I am starting to get frustrated. I can walk significantly faster, but really want to run and have to intersperse walk breaks almost all of the time still and don’t know where to go from here. MAF tests are improving – but at this rate I will get back to 12 minute miles in about 5 years (frustration speaking). No medications and I am currently 54. 50+ miles per week consistently. Thanks for any input.

    • Maurine:

      What do you mean by “slower maximum?”

      • Maurine Lee says:

        Where he recommends subtracting 5 points from the 180-age calculation. There are still many days where I cannot even run more than a half mile at very slow speeds before I am maxing out my HR – after all this time I would expect that to be improving.

        • Maurine:

          In Girl Gone Tri I made few comments explaining why some people develop faster than others. Let me recap that here for you:

          Genetics aside (which you can’t change), most people are encumbered with a lot of negatives inhibiting their athletic performance: too much stress, bad biomechanics, bad nutrition, etc. The more stress, the more your body works anaerobically (which is why chronics stress is so damaging). So, when you’re running at MAF and you’re not improving well, it’s not because the method “doesn’t work for you” but because there is one (or ten) negatives to your lifestyle, upping your stress, and not letting your aerobic system develop, because you don’t even get a chance to use it.

          So, your MAF test diagnoses more than just increases in aerobic function. It diagnoses when there’s some important factor preventing aerobic development. Find it, change it, and if it’s the right one, you will see that your MAF speed rises.

  • Mikko says:

    I’ve been using the formula for the past three weeks and I seem to be going over the limit all the time. I’m 37 years old and I’ve used 145, which was automatically set by my Polar-HR-monitor. However I seem to be going over as soon as I start running and I have to get back walking again. This happens especially on roads.
    Today I manually set it on 150 and I managed to get it below that limit almost all the time on trails. My average heart rate was on a one hour run 136 and max rate was 154.
    I have been running continuously for about 3,5 years and completed few self supported ultras during the time. I’ve never been a fast runner, but I’m continuously trying to expand my range as an ultrarunner. My current best time for 50-miles is 10h and 25 minutes.
    Is it okay to “cheat” and have the monitor on higher limit and TRY to keep it under 143. Or do you think it would be wiser to set it manually down to 143 to get the maximum benefits in the long run?

    • Mikko:

      The most important part of all this is that your aerobic base does actually improve. I would go by your monthly MAF test. If your MAF test is improving, keep doing what you’re doing. If not, then you shouldn’t be “cheating.” 150 isn’t that much higher than 143. That said, another question you should ask your monthly MAF test is whether you are improving faster by running at 150 or 143.

  • Andrew Rae says:

    Will this technique of training at a lower intensity still be beneficial if I reintroduce some carbs back into my diet after the two week test? If I go on holiday will I need to detox again?

    • Andrew:

      Yes. The point of the two-week test is not to eat that way forever, but to be more sensitive to the amount of carbs (or type of carbs) that works for you. What you shouldn’t reintroduce are foods such as refined flour, processed foods, or high-glycemic foods. Most people that take the two-week test take it because they experience symptoms of carbohydrate intolerance (headaches, fatigue, drowsiness after meals, energy swings, etc.). Those symptoms typically disappear during the test. So, if you go on holiday, look for whether those symptoms reappear and recur. That will tell you if you need to detox again.

  • Mark R says:

    I have just started using your 180 method. I am 47 with coronary bypass 6 months ago. I have enjoyed the pace of the workout but and curious about transient heart rates. I easily get to 133 but tend to over shoot to 138-142 on the high side and dip to 125 on the low. How important is to maintain 133 and do the temporary overshoots hurt my workout?

    Thank you

    • Mark R:

      Don’t overthink it. However, it’s important to be on top of your heart rate to bring down your heart rate below MAF as soon as it spikes. Going over MAF means exercising anaerobically. So think of it in terms of degrees: the more time you spend over MAF, and the higher the intensity, the more your exercise becomes anaerobic. What a lot of people do (including myself) is train 5-10 BPM below MAF, to allow for fluctuations in the heart rate.

      • Mark R says:

        Thank you. I have been able to achieve faster runs with a higher heart rate, but at the expense of a long recovery. I’ve noticed a very good workout with your method and a much quicker recovery

  • I’m curious about relationship between MAF heart rate and the exercise zones implied by Fox and Haskell chart shown here: For example for 65 y-o, MAF heart rate is 125, i.e., 115 plus 10 points for being 65. F&H show 124 bpm as being the threshold between anaerobic and aerobic training. I’ve always understood MAF heart rate to represent precisely this threshold–i.e., don’t go above it else you’ll be training your anaerobic engine rather than building up capacity for distance races such as marathons. The fact that MAF heart rate is nearly identical to F&H threshold seems consistent with that understanding.

    Here’s the puzzle. The MAF method also says you can add 15 bpm as your target HR while racing. That makes me think that the MAF heart rate is perhaps intended to correspond with the LOWER boundary of the aerobic training range, which F&H table says is 109 bpm. If so, one could still safely add 15 bpm and still be at the top of the aerobic zone instead of spilling into anaerobic zone etc. My puzzle is that everything I’ve read about MAF heart rate treats it as an absolute ceiling rather than a floor. But if one trained even 1-3 bpm below the MAF heart rate (to avoid even the possibility of exceeding the ceiling), then F&H chart says you’d no longer be in aerobic training zone, but instead would have entered fitness/fat burn zone. That makes me think MAF heart rate must truly be a ceiling, i.e., the upper boundary between anaerobic/aerobic. But if that interpretation is correct, I don’t see how one could add 15 bpm to the training target since that would clearly put someone into the anaerobic range. If they tried this in a marathon, wouldn’t they then quickly build up lactate to the point of being fatigued?

    Note that my confusion arises even if you think F&H chart is bogus. That is, if MAF training heart rate target truly represents the upper boundary between aerobic an anaerobic training, then I don’t see how one can safely add 15 bpm on race day. Thanks for the excellent feedback you provide to queries on this site.

    • Christopher:

      Thanks for your comment. It’s a very good one, by the way. Let me back up a little bit and discuss the aerobic and the anaerobic threshold. The aerobic threshold, when usefully defined, refers to the onset of lactate production, meaning that anaerobic channels are being used but the aerobic system can very easily buffer lactate production, and so lactate doesn’t accumulate. On the other hand, the anaerobic threshold is the onset of blood lactate accumulation, meaning that enough lactate is being produced that the aerobic system can no longer buffer it.

      The idea of the MAF heart rate is for it to coincide roughly with the onset of lactate production, in other words, the onset of usage of anaerobic channels. The reason that the 180-Formula adds or subtracts from your age, depending on your health and fitness status, is that stressors (such as an illness, or exercise itself if you’re sedentary) can often put you into an anaerobic state. For example, if I would sneak up behind you and startle you, your body would start burning energy anaerobically in anticipation of running away. The problem with the Fox and Haskell chart is that it doesn’t account for these factors. Although it is very useful when describing populations of individuals and population means, it’s not as useful when trying to establish where an individual’s particular aerobic zone lies.

      I think that one of the problems with the Fox and Haskell chart is that it doesn’t usefully define the terms “aerobic” and “anaerobic,” as I did above. Strictly speaking, everything up to the anaerobic threshold is aerobic, and everything up from the aerobic threshold is anaerobic (no, no typos here). Between the aerobic and anaerobic thresholds, you get a blend of aerobic and anaerobic function. What the MAF heart rate describes is the maximum point where you are functioning purely aerobically.

      So, when you add 15 BPM on race day (if you’re talking about a marathon) you are putting yourself between thresholds, blending aerobic and anaerobic function. For example, my MAF heart rate is 149, and I can run at it for hours without hitting the wall. Why is this important? Because hitting the wall means that you’ve been using enough anaerobic function that your liver glycogen got depleted, and now your brain and your muscles are in competition for blood sugar. If this hasn’t happened at mile 30, I know that I have been burning energy overwhelmingly aerobically. That is the experience of most other people, and incidentally, that is one of the observations that Dr. Maffetone used to develop the formula. In that sense, it’s not that I think that the Fox and Haskell table is bogus, but rather that the terminology used for each zone is misleading.

      • Paolo says:


        I’d have a very specific question to ask: a month ago I did a blood lactate test to figure out my thresholds. I ended up with 143 BPM as the aerobic threshold (2 mmol/l) and 158 as the anaerobic threshold (4 mmol/l).
        Since I have a MAF threshold of 138 BPM according to the formula, should I take 143 as my threshold (and so train between 133 and 143) or do you suggest to keep 138? And in this case, what’s the difference between the MAF threshold and the aerobic threshold measured in a lab?

        By the way, I’m 47, my marathon pace is currently slightly less than 7’/mile and training for a sub 3hour marathon this spring.
        A couple of years ago, after 15 years of amateurial running, I was convinced I had “plateaued” my performances: regardless of how hard I was training, my race times got worse and worse and I began suffering injuries now and then.
        Well, I decided to take it easy, I gave up my target of breaking the 3hour wall and, by chance, I discovered the benefits of slowing down during the training sessions. To make a long story short, this winter I run my personal bests in the marathon, half, 10k and 5k. Shaving minutes out of them. And since it was getting better and better I decided to take a more “scientific” approach: following our articles and dr. Maffettone podcast, and taking specific lab tests. That’s why I’d like to further fine-tune my training knowing more about the relationship between the aerobic threshold (lab-tested) and the MAF threshold.
        Thanks in advance for your answer.

        • Paolo:

          Typically we suggest that people go even below 2 mmol/l. In other words, the MAF HR should be just before blood lactate starts to rise (aka 1 mmol/l). In other words, if you’re trying to do “aerobic training” you need to be just a few beats per minute below your aerobic threshold, rather than actually at it. This is why the MAF HR is situated just below.

  • BJ says:

    Just wanted to add my experience here. I started following the program in late June, after continuously running into struggles with cramps, fatigue and nutrition on long runs & races. After reading about the MAF 180 method, it made sense to me. I looked back at my effort over the past couple years. I was training too hard, too fast, too often! I was on the path to OTS and it didn’t look good. I looked into MAF a bit further and found out about the difference between slow & fast twitch muscles, what they use for energy and which is best suited for which type of activity. i finally had something to work with going forward. I was willing to give it a shot because my approach needed a change.

    I started out very slow, sure… but was (still am) adamant about staying at/under my MAF heart rate (I’m 40 but have been training for several years without injury, luckily) which I find between 140-145. long runs, short runs, big vertical and flats it didn’t matter. i hiked and walked if I had to and focused on 15 min warm-up with at least the last mile in cool down. everything slowed way down, but I started feeling *tremendous* after each run. I even started getting Runner’s High again!

    this past weekend was a great reminder, after 8 weeks of consistent MAF training. I went for a 30-mile run up in the Colorado high country (9k-12.5k altitude) but forgot my HRM. I focused on staying steady and hiking where I needed to based on my perceived heart rate. I ended up finishing the run feeling fantastic! I was immediately able to eat a hearty meal afterwards, I didn’t suffer from any cramps, no puking or nausea and I actually ended up with with lots of leftover energy afterwards to devote to my 2 little ones at home.

    This is a big breakthrough for me as a mid-pack competitor more focused on finishing well/feeling great than placing. I do believe that by following the MAF approach these past 8 weeks, I’ve slowly-but-surely built more endurance and have more overall energy. I think this is another key to longevity in my running and adventures. May not work for everyone but I am seeing the difference and plan to continue on the path.

    Thanks so much for sharing this method and increasing the discussion!

  • Sebastian says:

    Hi Ivan,

    Could you please advice on what (if any) to eat before my runs. The only time I can train is in the morning so I get up early (5AM) drink a glass of water and do my 1 hour training. It usually take me another hour before breakfast. I’m raising this question because on one hand you advice to eat breakfast within an hour after wake up. On the other hand, Dr Phil recommends in his books not to eat anything (especially carbs) before training. Thank you.

    • Sebastian:

      A great way to start the day is by drinking a cup of coffee with some heavy cream (organic and unpasteurized, ideally) in it. That’s a great ketogenic meal, and a great way to kickstart your metabolism. That amount of cream shouldn’t be heavy enough that it interferes with your training. Try it. Let me know what happens.

      • Sebastian says:


        Thank you for your response. Important message for me is that it’s better not to exercise on empty stomach and it’s fat that I should eat. However, could you please confirm coffee is good just before exercise? I vaguely remember from the Big Book of Fitness that Dr. Phil suggests not doing so as it may raise heart rate. Can the coffee be replaced with tea without the risk of raising my heart rate.


        • Sebastian:

          Sure, it does that. The reason I mentioned it is because caffeine is pretty good at elevating your fat-burning ability (thanks to the fact that it unleashes a convenient cocktail of hormones). Phil drinks that in the morning but I guess I didn’t consider the exercise factor. You should try a herbal blend tea without caffeine, and see if that works.

    • Sebastian says:

      Hi Ivan,

      Could you please advice if good carbohydrates should (or can) be included in my breakfast after MAF training? I was avoiding mixing good for me carbohydrates with proteins and fats during my meals in order not to disrupt digestion. I’m trying to eat carbohydrates between my meals alone or with fats.


      • Sebastian:

        I’d go with low-glycemic carbs and stay away from starches. I think that a really good example of a post-workout meal is Phil’s Shake. Ideally, during your MAF run you were burning fats at a very high level, so you shouldn’t be glycogen-depleted. But generally speaking, what I do is emphasize fats at breakfast, proteins at lunch and carbs at dinner (plus making each meal of decreasing size a.k.a. caloric content). The reason for that is because I’m not really going to get glycogen back into my muscles and liver unless I’m at or below 1 MET (a.k.a. sleeping). So I kick up fat-burning in the morning, use glycogen throughout the day in a sustainable fashion, and set myself up to replenish it at night.

        If you’re doing your MAF runs right, fat-burning should be really high throughout the day so you shouldn’t worry about your blood sugar levels or energy that much.

  • Michelle Keene says:

    Hi there,

    I am training for the Marathon des Sables in April 2016. I too am struggling to get my HR down to what is suggested when I do the formula. My plan for the MDS is just to finish it which will mean a mixture of walk/jog. I have about 7 months to get myself fit and ready for this event and am worried that by sticking to this formula the training is not intense enough. I am already a fairly fit person, ex marathoner etc. I also need to train with my back pack on so that I get used to carrying the weight in the desert. This also affects my heart rate so again I’m not sure if this formula is the right thing to do for this sort of event. Any thoughts or comments would be greatly appreciated.

    • Michelle:

      Thanks for your comment. The Marathon Des Sables is an event of phenomenal endurance. Your best bet is to train your aerobic base. Although your heart rate will go up above your MAF heart rate for the race, thanks to the pack, the more aerobic your training, the better chances you will have in the race. Your anaerobic workouts, for example, could be running with the pack to get used to it.

  • Bill says:

    I have some questions about how to apply the formulas to my case since I seem to fall in almost all the grey areas.

    My background is that I used to be nationally ranked in super-long ultramarathons (more than 100 miles) but haven’t trained rigorously for 6 years. While I haven’t entirely quit training, I also can’t say that I’ve been regular in the interim. I am in great health, take no drugs, medicinal or otherwise, and never get sick. I should also probably tell you I bought Phil’s The High Performance Heart back in 2000 and used it to develop my aerobic efficiency.

    Here is the math for me:

    Step 1: I’m 67, so 180-67 = 113.
    A. I wrote a month ago (July 29) that I just fixed that irregular heartbeat, said I was perfectly willing to pretend it was major surgery (it’s not. It’s an out-patient procedure), but at some point it would be far in the past, asked when it was OK to ignore it. The answer I got was to check with my cardiologist. I did. He’s OK with my exercising at a fairly high level now. The restriction I’m putting on my HR level is coming from me, not him. Since I am temporarily: 113-10 = 103.
    B. My workout routine has been inconsistent for a while, though, and I am just getting back into regular training. So 103 – 5 = 98.
    C. On the web site you say if you’ve been working out consistently up to 2 years, then keep the heart rate at 180 – age, but the key phrase is “up to 2 years.” In the book, he wrote it as, “If for the past year if you have worked out consistently…” but the book was written 21 years ago according to the copyright. The website is more current and doesn’t have that 1 year minimum. That begs the question: After how much time of regular training can one (in general) or I (in specific) go back to 180 – age? It’s no longer specified. Nevertheless, no effect yet. Still 98.
    D. I don’t fall into this bracket yet, so again, no effect. Still 98.
    That gives me a training range of 88 – 98.

    However, I am 67. That means I theoretically have another 10 points I can add back.

    My conundrum is that based on all the grey areas, I have a huge range of possible training zones:

    We just figured my low end as 88-98.

    Without my lowering the HR by 10 (as Ivan said was OK as long as it was OK with the cardiologist), that would be 98 – 108.

    At some unspecified period of time I will have been training regularly long enough to no longer have the 5 beat reduction of B, so that takes me up to 103 – 113.

    And then there are the additional 10 beats I have available to add because of my age. That would take me potentially up to 113 – 123.

    See my problem? I don’t want to over-train but I also don’t want to grossly undertrain either. I want to train in the right zone. If my MAF Max (I don’t want to call it ‘my maximum heart rate’ because I have noticed way too many people’s comments center around a simple confusion of terms, thinking when you say, “maximum heart rate”, you mean what the words mean – the maximum rate your heart can beat, whereas what you actually mean is the maximum heart rate allowed by the MAF formula. For our discussion, how about if I call it my MAF Max?) … so if my MAF Max should be around 120, keeping it below 100 is not doing me that much good.

    So, what do you think my range should be? Remember, I’m the one being cautious regarding A and Ivan’s earlier response said that when my cardiologist is OK with it, it is OK to add those 10 beats back and he’s OK with it now. My plan was to continue being overly cautious for a month and then over the next few months slowly starting adding back. But to what level? What would you advise? I’m not clear on what my MAF Max should be since I fall into all of the grey areas. I could use some help figuring out the right training zone.

    Thanks in advance!

    • Bill:

      Your range is probably 103-113. You don’t need to go below that, and you can play with going above it if in a couple of weeks of training you don’t seem to be improving.

      That said, remember that the MAF heart rate isn’t a “training” heart rate. It’s the best heart rate for aerobic development. There’s no such thing as a “training” heart rate—at different heart rates you train different energy systems. You only want to train exclusively at your MAF heart rate IF:

      • You are ill, injured, or overtrained.
      • You are recovering from injury, illness, or overtraining.
      • You are building your aerobic base.

      This is important because of the indoctrination we’ve received in contemporary workout philosophy: more volume, more intense, is better. It’s not. So, when you’re attempting to train your aerobic system (because you fall into one of these categories) it’s important to make sure that you are training at a heart rate that is sufficiently low that you are actually doing that. That’s what the MAF heart rate is. With this in mind, let’s look at your case:

      • Your cardiologist cleared those 10 heartbeats. You’re sure about that.
      • You’re unsure whether you should add 10 more heartbeats

      Because training the aerobic system is about being conservative with your heartbeats, then be conservative. Since you’re sure about what your cardiologist said, you don’t need to be conservative there. But because you’re unsure about the other 10 BPM, don’t add them. You’re not going to “undertrain” in any real sense of the word; by being conservative you’re just going to ensure that you’re training what you (presumably) need to be training at this point—the aerobic system. When you’re ready to train the anaerobic system (which on average you’re ready for after 6 months of improving MAF test scores after being overtrained, or 3 months of improving MAF test scores during aerobic base building), 15-20% of your total athletic activity should be done anaerobically, and the rest should remain aerobic.

      While you’re training the aerobic base, you want to go actively low. When you’re training anaerobically, you go actively high.

  • Katie LeSauvage says:

    I am working with a renowned PT and he is a proponent of the Maffetone Method. I am going into my second week using the 180 formula. For me, that is 180-36(+5)=149. Where most people are saying the find themselves running so slow, I am finding this to be effortful. Although I start out at 9:30 pace, within a few miles I am running closer to 8:00 and have to push myself to keep my heart around 140. I’m not exactly sure what this means. I also attempted the 2 week test last week, but only made it 4 days. I have continued to keep my starches/sugars relatively low, so don’t know if the effort felt is the result of my body not being effective at burning fat yet. Still, I am quite confused as I don’t know why it feels so hard, which seems to be the opposite of most others experiences. I typically race around 6:30-6:40 pace for 5K/10K, so 8:00 really isn’t slow. I’d appreciate any thoughts!

    • Katie:

      Thanks for your question. The reason that you perceive running at MAF to be difficult is because you already have a pretty developed aerobic base, particularly when it’s difficult at that speed. Perceived exertion refers to how much “voltage,” so to speak, your brain has to send down the nerves to your muscles in order for them to contract at a particular rate. In your case, this means that your aerobic metabolism is powerful enough that your brain needs to send a whole lot of voltage to your muscles to keep them working at the MAF heart rate.

      The reason that most people perceive MAF to be very easy is because they have a very undeveloped aerobic system: their aerobic metabolism is so weak that their brain can send relatively little voltage to their muscles before they have to start using anaerobic channels.

      I’m not sure if this metaphor is illustrative. Please comment back if this makes no sense.

  • cori says:

    Hi, I have been struggling to build cardio endurance while maintaining muscular strength for a very long time. I have been successful at building and maintaining strength, but completely unsuccessful with cardio end of it. I am 63 years old, have diabetes 2 and asthma. I take daily drugs for both. If it matters, my resting HR is presently 38. I am currently in the worst shape of the last 15 years, frustrated, but am very serious about making improvements. From what I have read and the little I know about training, the Mafftone formula seems solid. I get a sense that the idea is to build a solid zone 1 and 2 base. I am very much looking forward to getting started on a good program consisting of 3 days strength and 3 days cardio, however, I’m not sure how to combine the two. When weight training my HR generally reaches mid to high 130’s. Although I challenge myself a bit, I don’t go overboard with the strength training. The purpose is simply to maintain some muscle to ward off osteoporosis. When trying to maintain 102 for cardio, I am walking briskly. A very slight rise in the grade (not necessarily a hill) will put me into 125+ very quickly, then it will drop again. Fairly normal I think. I am estimating my Maff settings at 150 – 63 = 117. Then minus 10 for regular drugs , and another 5 for chronic asthma. The bottom line = 102. Is that correct? My questions are: Have I calculated the Maff zone correctly? How do I manage some strength training while trying to maintain the 102 HR. I would appreciate your suggestions. Cori

  • Katie says:

    Individuals seem to be commenting that their pace is quite slow when running at their MAF heart rate. I am guessing this is not the case as someone improves their aerobic fitness. My MAF heart rate is 149 (180-36+5). I usually start on at 9:30 and today got down to 7:45/mile with my heart rate still under 150. I tend to think that sub-8 minutes is fast for base work, but I guess I should go with the heart rate which indicates it is not? It is effortful, but I feel like I could run at that pace for a long while. Ideas?

    • Katie:

      Intensity is a measure of heart rate, not of perceived exertion. For example, an elite marathoner would be doing base-building at 6:30 minute miles, at a heart rate probably lower than yours. In other words, “fast for base work” may be sending you down the wrong path. If you’re at the right heart rate, you’re at the right intensity, and that’s where you should be training.

      Incidentally, the reason that perceived effort rises is not because you are training any more anaerobically, but because your aerobic metabolism is powerful enough that the brain needs to send very powerful signals for the muscles to contract at the rate that your aerobic metabolism can handle. In other words, perceived exertion doesn’t have to do with whether you are training aerobically, anaerobically, or at any given heart rate, but rather how much “voltage” your brain is sending down your nerves, relative to its total available “voltage.”

      What this means is that metabolic output, which is what you’re wondering about, is actually unrelated to perceived exertion: more perceived exertion does not necessarily mean more metabolic output.

      Does this make sense?

      • Katie says:

        Thanks so much for your responses to my questions. That makes sense and has increased my confidence that I am on the right track. I look forward to learning more as I further explore the site and books on the method. Thanks for being available to provide clarification.

        • Katie says:

          I’m back with another question related to the same ideas. I did 3 weeks exclusively at my MAF hr (149), then understood my aerobic conditioning to be good, so this past week added 2 tempo runs (3 miles each, one at 7 min pace, one at 6:40 pace – both HR were 165-172 range). This morning, I had to run EVEN FASTER to keep my hr around 149 (aim for 140-149). Where I had been starting out at 9:30 pace and getting down to 8 min, today I started out at 8:04 and got down to 7:14 (total run 7.75 miles). This has occurred within a 4 week period and my perceived effort just seems effortful! If I let up the slightest bit, my HR drops to below 120. From your prior response, I understand that my brain needs powerful messages to keep working at my MAF hr. How can I impact that through training, as I would like to run fast without perceiving such a high effort? I also started eating low carb/high fat diet 4 weeks ago, so don’t know if the effort is being perceived due to my fat burning system not being optimal yet. Let me know if you think that might be part of the issue. Thanks so much, again! Have said all is, I am very happy with the quick results…just looking to understand things better.

          • Katie:

            Strength training. By increasing the maximum power that your brain can put into your muscles, you’re also increasing it relative to your aerobic ability. When the same movement with the same power takes up a smaller percentage of your total brainpower, it becomes less perceived effort.

            Make sure that my recommendations amount to no more than 15-20% of your total training volume. 80-85% of your training should still be at the MAF heart rate.

            I’d say start by doing wall pushes (the idea being to try and push down a wall). You’ll notice that you’ll intuitively have one foot forward and one foot back. Notice how this posture mimics the running gait—that’s why it’s so useful. With your arms fully extended and parallel to the ground (but with elbows unlocked), push as hard as you can for 10 seconds. Rest for a minute and switch feet. Repeat 3 times.

            Do this for a week to 10 days.

            What you’re doing with this exercise is teaching all the muscles of your body how to engage fully with one leg flexed and the other fully extended (i.e. in the end ranges of motion of the gait cycle).

            Then, do 3 five-second sprints with 30 ish seconds rest in between, to utilize this new knowledge in the running movement. Notice that even though we’re using the body here, the idea isn’t to tire it. The idea is to produce exertion, so that the brain understands which way it needs to develop.

            Then, once you’ve done this for a week to 10 days, do weighted sled training. Figure out a reasonable amount of weight to put on an exercise sled. Then push it for 20 yards as fast as you can. Rest until you’re breathing easy and repeat for 3 times total. See the logic? First you got strength and stability in the end ranges of motion, and you integrated that into the running gait. Now, you’re “filling in” that strength in the whole range of motion. Again, once you’re done with the 3 sets, do 3 sprints as indicated above to pattern this into the running gait.

            If you don’t have a running sled, tie a 25 or 35 lb plate to your waist with a 6 or 8 foot rope. You want to drag this behind you, but it’s the same idea as the sled. The effects of pushing and pulling are different in the body (and would both be part of the training of a competitive athlete), but as long as you pattern that in with sprints, you’ll get a lot of benefit even without pushing drills.

            Do this also for a week to 10 days, and then go back to 100% MAF training for about a full month.

  • Laura says:

    I have been athletic and competitive my whole life, and realize I have most likely been training in the anaerobic zone the
    majority of the time. I just bought my 1st HRM at age 54, and plan on rebuilding aerobically. I have not read all of the comments, so please excuse me if this has been covered — but why is one’s resting HR not part of the formula? (Mine is 42) I would think that someone
    who has a resting HR of 60 or 70 at the same age wouldn’t be bringing their rate up in the same number of beats, and therefore
    might be in a different zone. Am I missing something??

    • Laura:

      First off, nobody “just has” resting heart rate X. Resting heart rate X is derived from a multitude of factors: genetics, training, present stress levels, etc. And what “genetics” means is this: that someone’s aerobic system powerful enough (or their heart has a stroke volume such that) they can have resting heart rate X given the environmental conditions they find themselves in. In other words, a “naturally high” resting heart rate always means “a resting heart rate that implies that a person’s cardiovascular or metabolic power is naturally (read:genetically) lower than the norm, such that their metabolism (and/or heart) has to work X heartbeats more strongly to meet their basic upkeep.”

      Now, let’s put this into context: Think about the MAF Test. The heart rate by itself isn’t important. What’s important is the athletic output that you can produce at a certain heart rate (in other words, your MAF Speed).

      Suppose you have two people with an MAF heart rate of 150, but one of them has a resting heart rate of 70 and the other a resting heart rate of 40. The one with the resting heart rate of 70 has a metabolism (and/or a heart) that is working harder, relative to its maximal athletic capacity (a.k.a. MAX heart rate), than the person with a resting heart rate of 40.

      If, for both people, one BPM means a running speed increase of .1 MPH, then the person with a resting heart rate of 40 will be able to run at 11 MPH, while the person with a resting heart rate of 70 will be able to run at 8 MPH. In other words, the 180-Formula doesn’t need to use resting heart rate because the MAF test gives you your adjusted athletic output: the maximum output of your aerobic metabolism minus your resting heart rate, a.k.a. the metabolic work your body had to do just to meet its basic upkeep.

      In other words, for all intents and purposes, someone with an MAF heart rate of 130 who is under chronic stress (and therefore has a resting heart rate of, say, 110) might be existing in zone 2 or 3).

      If you have a resting heart rate of 42, all things considered it means that you are 18 heartbeats fitter (which again “fitness” is relative to your environment) than someone with a resting heart rate of 60. The best example of how fitness is relative is when you travel to a hotter climate or greater altitude: your resting heart rate rises because your metabolism needs to do relatively more work in these less hospitable conditions to provide your body’s basic upkeep.

      I hope this helps.

  • Jim says:

    Hi Ivan,
    I took your advise and stopped using a timer with intervals to maintain my aerobic HR (180-76)+10 =114 b/min. Did an initial aerobic function test last week (1 mile on a 1/4 mile track) Warmed up and when HR was at 112 started the test. Stayed right at 112 -114 but noticed each 1/4 was slower than the preceding one and they were all agonizingly slow starting out at 18:00 pace and ending at 20:35. What do you make of this? I’m 76 years old and I can walk the mile in 17:10 at a HR of 90 b/min. Should I just give it more time running at or below 114?
    Thanks in advance for any suggestions. I really getting a lot out of this site.

    • Jim:

      Running is often slower than walking when you have an undeveloped aerobic base for the following reason: When you run, you take off, which means that your leg muscles have to absorb the shock of landing, while this doesn’t happen in walking. This means that for walking and running at the same speed, running will have a higher metabolic cost.

      Given this disadvantage, why do we run? Because running lets us achieve far greater speeds than we ever could walking.

      Now, let’s consider what this means for training: even though you may be running slower, your metabolism is still getting developed faster. That’s what really matters. The metabolism is what lets the muscles develop, and it’s also responsible for the muscles’ upkeep. In other words, even though it may be frustrating, as long as your heart rate is higher than walking, you’re getting more out of your workout. (That said, the important thing for you is to keep it at or under MAF in order to maximally develop your aerobic system.)

      So, how do you get around this frustration? Two things: first, try walking faster. Accelerating your walking gait, cadence, and using your arms to help drive your legs will increase your heart rate, increase your speed, and increase the metabolic cost of walking. That may get you up to your MAF heart rate. While you do this, supplement with jumping rope, focusing on flexing and extending the knees (rather than keeping them straight and bouncing up and down on your calves). Why jumping rope? Because this will teach your body how to perform the takeoff and landing—the part of running that contributes to your present reduction in speed.

      At some point (maybe in a month, maybe in 2), if your walking speed at MAF (or at sub-MAF heart rate X) has increased, take a shot at running. You might find that either you can do so with no reduction in speed, or that you’re further along than you were before.

      • Jim says:

        I took your advise and tried jumping rope slowly. That worked as far as HR goes but it was hard to keep up. I did get an idea from the experience though, that was cadence. I noticed that when jumping rope without engaging the calf and achilles directly that the frequency was slower. When running I normally have a cadence of 175-180 steps/min. So I tried jogging at around 160 steps/min and that worked. I can now keep my heart rate at 104 to 109 bpm easily. I’m still running slowly but it feels easier. Perhaps the leg/foot system has multiple natural frequencies?
        Thanks for your suggestion

        • Jim:

          There is research that says that the lower limb system is not only optimized to multiple frequencies, but is rather expressly “designed,” if you will, for being able to vary frequency safely and successfully. It’s a pretty logical evolutionary adaptation for a being that can express a wide array of behaviors.

          One of the ways to work on getting faster (I myself had to go down to 9:45 minutes/mile when I started running MAF) is to increase your speed in function of increasing your stride rate. This will mean over time engaging the entire posterior chain (including the calf and achilles).

          Let me know how it works for you.

  • John 997 says:

    Hi Ivan
    I am a 61 year old and have been mountain biking with two groups for 6 years. They range in age fron 25 to 55 but mostly around 40. I did my first ever race 2 weeks ago. It was 30m and about 6,000 ft of climbing on Singletrack. I got 2nd place at 5 hours 50 minutes. I was really pleased. I found it very tough especially after 4 hours.
    I wondered if there was a better way to train. The guys I ride with start by sprinting up the mountain at home. It’s usually an hour with a few stops to let the slow ones ( like me ) catch up.
    We stop at the top and then fly down on open mountain amaybe do some trails and finish after 3 hours with a sprint home.
    The other group are slower and focus more on downhill. I go out with them on Sunday for about 2 hours.
    Reading your book I see why this was all wrong and I am looking forward to trying the 180 formula
    I am not sure if my ride of 3 hrs on Saturday and 2 hours on Sunday put me in the +5 ,zero or – 5 category for heart rate adjustment.
    I don’t get any other exercise except an occasional round of golf.
    Please advise as I am keen to start.

    • John:

      Use the 180-Formula to your best judgment. That said, it pays to be conservative. (For example, my own MAF heart rate is 148, but I usually stay at 144 or below). If you don’t think you have any relevant health issues or aren’t taking medication, then I’d say you’re probably a +5. BUT if you haven’t been showing improvement, go for a 0.

  • Grant says:

    I came across this site 2 weeks ago and am really fascinated with the training concept and have adopted the 180 formula completely in my training these last 2 weeks. Everything discussed here and a lot of the comment responses make sense to me and I can understand the science behind what you suggest. I looked at my training over the last couple of months and realised that every session was anaerobic. From long Sunday runs to hard group rides, to sprinting hills etc. I was improving sure, but felt tired, often finished a session and was dreading the next (as I knew the intensity would be high), I was starting to feel overtrained and losing motivation. Also I was constantly looking for high carb, sugars for energy to help fuel the intense sessions.

    So 2 weeks ago I made the switch at the end of a hard training block. I decided to just run 50km in the week split into lots of runs and being 31 my MAF was 149 +5 (154). So first run was a little bit of a shock at how much slower ‘slow’ actually was, any little hill I had to be super careful not to spike over the 154 and was often shuffling. However I finished the 8km loop with an average pace of 5:35 min/km. I couldn’t believe how good I felt at the end of the run, it was enjoyable, I was not remotely sore and best of all I felt like training again. So the next day I went out for a 7km run in the morning and a 7km run in the evening. Same thing!! Felt great, recovered well and was keen on my next session. I mixed in some bike work over the next few days and some more runs before finishing with a longer run on the Sunday which is where I was shocked. I did a 60 minute undulating loop and was able to average a pace of 4:51 min/km while not exceeding 154 HR. I even found on some of the flats / small downhills I really had to focus on lifting the pace to get my HR back up as it would drop even below my 10 heart beat range (144-154), often down to 120-130.

    I know a MAF test is meant to only be conducted every 3-4 weeks but I was super interested watching it each session (not getting hung up on it and knowing some run loops were hillier but still very interesting to watch).

    The 2nd week I decided to mix some more bike work into the week. I noted a few other sites which reference MAF that they adjust the bike HR, and this is where my questions start. I started with some 45 minute rides and 25 minute rides to see how I went. I noted that unless I was on a hill I would have to work hard to get my HR to 154 (or just below). On a slight downhill forget it. On a hill sure, it was easy, I was having to really slowly pedal up (often dropping desired cadence) to ensure it didn’t creep over. I also noted that if I was working at 150-154 HR on a flat course then my legs were starting to burn. So why is there such a difference in experience between running and the bike? I still feel fine after a bike, and recover well. I did a 2 hour ride on a very undulating course yesterday and felt good but I wouldn’t say I had the same feeling of I could hold this pace all day, unlike the run.

    What is the burning feeling? If I am working aerobic then I shouldn’t be creating lactate right? Why the discrepancy between running and riding? Also I want to ensure I don’t overtrain, but it sure does feel like you can do as much of this aerobic work as you wish. I am often training twice a day with either a ride in the morning and a run at lunch and feel fine. I slot in a rest day when I feel like I need a sleep in or my muscles are a bit tired (mainly from the riding).

    I have also adjusted my diet and cut out as much sugar as I can, while also reducing the volume of carbs. I always train in the morning on an empty stomach but I want to really improve my ability to burn fat. So I am trying to increase the amount of fat I have in my diet to promote this while training MAF. Regarding the science here, does your body break down fat and turn it into glucose which is then used? So you are still using glucose but it is just coming from the break down of fat rather than sugar? I must say I am feeling a little tired at points in the day from the reduction in carbs, also probably due to not being able to increase the amount of fat in my diet / ability to use it well enough. I struggle for foods to eat also. Nuts, tuna, ham, fruit, vegetables, coffee with cream or butter, chocolate, avocado then I am stuck. I still eat some bread, rice and pasta but smaller quantities. I have lost 1-2Kg already.

    I have a triathlon in 9 weeks and wish I had come across this training ages ago so my last training blocks could of been solely MAF. However I will train MAF for another 2-3 week solely (total of 4-5 weeks) then will add 1 anaerobic bike and 1 anaerobic run to the mix to prime that energy system before racing. It will be no more than 20% of my training volume so MAF will still dominate. After which I will train MAF solely for 3 months to really build my aerobic engine. So excited to get a good proper base behind me and this site has really helped me re-focus and given me the perfect tool to apply on things I have known but for some reason ignored. Why the heck was I training all anaerobic haha!! So much cortisol!

    What is your recommendation on tapering? I think I read somewhere in the comments of a 80 / 70 / 60 / 50 / 40 / 30 / 20 idea of volume in the last 7 days and all MAF. That is race is Sunday so on the Sunday before only do 80% of usual volume and MAF only, Monday 70% etc etc. I really felt my 1st week of MAF made my body feel amazing so keen to avoid any anaerobic work in the week before, but do you suggest longer? Is there a decrease in anaerobic system performance after a certain amount of time. Similar to mitochondria loss after time in the aerobic system.

    Wow, sorry for the essay but excited to learn.

    • Grant:

      Generally speaking, you want to taper for 10 days for a marathon, 2-3 weeks for an ultra, depending on the distance, and less as the distance shortens. There is a decrease in anaerobic performance by not training anaerobically, but a lot of it has to do with optimization, rather than loss of infrastructure. Since the aerobic and anaerobic systems are not equal (the aerobic system is the foundation for the anaerobic system but not vice versa), losing mitochondria is a much bigger problem in terms of health or exercise performance than losing anaerobic infrastructure.

      A recent study showed that in anaerobic interval training, the performance difference between recreational runners and well-trained runners wasn’t created by an increased ability to burn sugar, but an increased ability to burn fat: sugar-burning between recreational and well-trained runners was similar, but the well-trained runners showed a threefold increase in the usage of fats.

      In other words, your ability to increase your speed beyond a purely aerobic intensity isn’t really based on your anaerobic system, but rather on your aerobic system. Of course, you need to train at high intensities to develop the contractile power for your muscles to be able to generate high speeds, but the ability to put those muscles to use at that intensity comes from the aerobic metabolism.

      That said, you don’t really need to go total MAF (besides 3 months a year for base-building) unless you’re injured, overtrained, or chronically ill. A simple 80% aerobic 20% anaerobic (where 20% includes both training and racing) is more than enough, provided that you do an MAF test every 2 weeks to keep track of your aerobic base.

  • Mike S says:

    I’m 69 workout 6 days a week for 45 minutes to an hour. I am not training for any races or competition.
    Just looking to be healthy.
    Is that too much?

    • Mike:

      Your best bet to figure that out is your MAF test. Test yourself now and then in a month under similar conditions, as per the instructions on the article. If your MAF speed drops, then yes, it is too much.

      However, if you have been exercising that way for a while without illness or injury, chances are you are on the right track.

  • fay says:

    thanks for taking the time to answer questions!

    I had a baby 3 months ago, I was fairly fit before – ran 5-10 miles a few times a week, and am trying to get back into running shape. With perfect timing, I read about the 180 MAF method in a running magazine and can’t wait to apply this to my getting back into it! My question is this- which category would pregnancy and delivery be considered under (normal pregnancy and delivery and was able to be decently active during pregnancy)? I am 27, and in good health – so would that be 180-27-10 for MAF of 143 or 180-27-5 for MAF of 148?

    • Fay:

      You shouldn’t worry about it too much. Just do the 180-Formula as usual but perhaps just ease into training over the course of a month to make sure that you don’t overstress yourself. If you feel well and aren’t under any medication (as per the instructions) then I think that 148 should be just fine. Again, if you find that your MAF speed begins dropping rather than rising, then take off those additional 5.

      The 180-Formula is designed to be conservative, however, so 5 extra BPM won’t catapult you into overtraining or anything.

  • Phil says:

    A few questions come up regarding adjusting my 180 formula:

    “b) If you are injured, have regressed in training or competition, get more than two colds or bouts of flu per year, have allergies or asthma, or if you have been inconsistent or are just getting back into training, subtract an additional 5.”

    First one is about just getting back into training. I started the MAF approach late July, and originally subtracted an additional 5 bpm from my max aerobic heart rate (180 bpm – 23 bpm- 5bpm =152 bpm) since I’m just getting back into training. Is there a certain amount of time where it’s considered that I am no longer “just getting back into training”? The reason I ask is because if the answer to that question is after 2 years of consistent training, then I would also fall into category d) “If you have been training for more than two years without any of the problems listed above, and have made progress in competition without injury, add 5.” If I category b) after 2 years (therefore adding 5 bpm), then at the same time apply category d) to my formula (an additional 5 bpm), that would jump my max aerobic heart rate by 10 bpm (180 bpm – 23 bpm + 5 bpm = 162 bpm). I can see increasing it up 5 bpm twice over two years, but is increasing it by 10 bpm all at once after 2 years realistic for an accurate max aerobic heart rate?

    My second question is still on category b). I do have seasonal allergies in the Spring due to pollen. Do I only subtract 5 bpm from my max aerobic heart rate during the Spring, and when I feel my symptoms? Or do I have to subtract 5 just because I’m prone to seasonal allergies in general (since we’re only heading into Fall and I won’t have those symptoms for a while).

    Thanks for taking the time to answer my questions, I truly appreciate it!


    • Phil:

      Thanks for your excellent questions.

      2 years of consistent training of any kind without injury is enough for the 180-Formula. If all you’ve done is 2 years of HIIT with no aerobic base building and somehow you haven’t had an injury in that period (unlikely), you’re good to go for those 10 BPM.

      About increasing those 10 BPM all at once, think of it in the opposite direction: You’re not increasing 10 if you’ve been training 2 years without injury, but rather 2 years of training without injury means that you no longer have to detract 10 BPM. The reason it’s best to add 10 BPM at the end rather than 5 and 5 is because, say, a bone that is 95% healed from an injury may only be able to withstand 50 or 60% of the stress of a fully healed bone.

      Think of the body as a twisted metal girder or a beam that you’re straightening so that it can bear more weight. If the girder’s full rating is 1500 lb, and a bend in the middle of 6 degrees means that it can only carry, say 1000 lb, then straightening it halfway (3 degrees) does not mean that it can carry 1250. Instead, it can probably only carry say 1100. It isn’t until you straighten it up to say .5 degrees away from perfect that its rating starts shooting up again.

      In that same way, a fully healed body may be 15 or 20% more resistant to stress than one which is only 95% healed.

      I hope my metaphors are illustrative. Please don’t hesitate to ask me for more clarification.

      As far as allergies, what usually matters are the allergy symptoms—they create a great deal of respiratory stress, which hastens the onset of anaerobic work.

      • Phil says:

        Hi again Ivan,

        Your metaphors helped a lot. Thanks for the input!

        I’ve been endurance running for about 4 years now. I don’t recall any injuries; I have mostly been good about how long I rest. However, since I did not wear a hear rate monitor, I can say with confidence that I probably used to train at too high of a heart rate since I went by pace and was reaching too far. But no injuries!

        With that said, since I’ve been actively training for over 2 years without injury, I might just try adjusting my base training to 157 bpm (180-age [23]) instead of 152 bpm. I would be running at 152 bpm with this new MAF heart rate anyways, since I have the same approach as you; running at 5bpm below MAF to allow heart rate fluctuation without spiking over MAF.

        Another question does come to mind: I live in New England, what are your thoughts on treadmill running amid the below freezing conditions? As I keep tracking my MAF test results at the end of each month, I don’t want to have the winter conditions slow down my pace and influence my results. I feel like with a treadmill, it’ll be a better reflection of my progression until it warms up again. Nothing beats running outside, but as long as I’m tracking results, I want to keep the conditions that I test in as consistent as possible.

        Again thanks for your knowledge. It helps more than you know.


        • Phil:

          When doing the MAF method, it’s important to keep 2 things in mind:

          1. Training isn’t racing
          2. MAF training is about the metabolism

          When you’re exercising at a certain heart rate, your metabolism is exerting itself at a certain intensity, regardless of whether it feels easy to you or not. (Perceived exertion is an indicator of something else). So, if your metabolism is going at a certain intensity (as indicated by your heart rate), it is getting trained that much. And if it is going at an intensity that allow the aerobic system to be maximally developed (MAF HR) then that is exactly what is happening.

          This is important when you consider that your metabolism (really meaning your aerobic metabolism) is far more responsible for carrying you across distance than your muscles are.

          So, while it’s important to cultivate and maintain muscle power, nobody is losing “fitness” by running slow in the summer as opposed to faster in the fall. If you are always training at a certain heart rate, then you are always training the same intensity (and by implication, the same energy system at the same rate).

          This means that you can train on the treadmill to run faster, but you are only training faster. You aren’t training more or better in any sense of the word, and by opting for the treadmill you certainly aren’t training your ability to go any faster once weather conditions allow, than if you had trained outside. The only important metabolic difference (which is why your speed is slower outside) is because your thermoregulatory systems are getting a workout. If that’s important to you, then run outside.

          That said, there’s another biomechanic difference: running on the treadmill stresses different muscles and (more importantly) creates different motor patterns than running outside. For an elite runner who’s run tens of thousands of miles outside, a thousand miles on the treadmill just doesn’t re-train them, because of the weight of their experience. But for the rest of us, getting “used” to the treadmill may be a problem, in the sense that by becoming de-optimized to a stationary surface, the metabolic cost of running may go up (for a while), and so for a while our MAF test may be slower.

          But again, this de-optimization (and the loss of speed associated with it) has nothing to do with fitness, but rather with the present neurological patterning.

          • Phil says:


            The treadmill feedback helps a lot!

            The reason why I have been concerned about my MAF test progress is because I want to be able to see when my MAF test begins to plateau, so I can switch from the aerobic base training phase and incorporate my 20% of anaerobic training. If I test at the end of one month in late fall, and then testing in the next month occurs in much colder conditions, I was curious if it’s possible to tell when it’s time to end my aerobic base training phase when cold conditions make your results fall out of the trend you’ve set in the Fall.

            I do understand that it’s all about training the metabolism specifically, and that training is not the same as racing!

            I may just be overthinking, but your clarifications are very knowledgeable and helpful.


          • Phil:

            It’s hard to know. What I can tell you is that you’ll see much quicker improvements in your speed when you are doing cold or heat training. Why? Because your aerobic base is presumably already developed. During cold or heat training you go into the anaerobic zone at the same speed for 2 reasons: 1, the thermoregulatory system isn’t capable, so it has to run at a relatively higher intensity to produce the same result. This means that you have to power it anaerobically if you don’t want to take it slow. 2, the aerobic base has to develop a little more to accommodate the increased functioning of the thermoregulatory system.

            That said, your aerobic base (AB) has been developing for a while, while your thermoregulatory system (TRS) has not. Your aerobic base is comparably more robust, meaning that while the AB has to increase its capability by say 10% to be able to incorporate the (TRS), your TRS has to increase its power by say, 50%. However, and this is the point, your TRS is much smaller (and therefore quicker in developing) than your AB. This means that in a week or two (the time it takes for hot and cold weather adaptations to happen in most people), you can expect to gain the majority of your speed back.

            All this only applies, of course, if your aerobic base was already at acceptable levels.

            I guess the best way to figure out when it’s time to end aerobic base training is to track increases: even though your absolute speed may decrease, you’ll see that drop because of thermoregulatory stress, but keep seeing increases (to the lower speed) after that drop happens. I’d say to figure out when the drop in temperature starts and when it’s 90% of the way there. Eliminate that time from your calculations, treating it as a confounding variable. Once 90% of the temperature drop has happened, if you continue to see increases like before, then it means that for that entire time, your aerobic base has been developing. So I’d just count it in.

          • Phil says:


            Great clarification. With that said, you’ve given a full understanding of what I’ve been searching for. Thanks again for taking the time to give such elaborate responses!

  • Ross Laird says:


    I just wanted to send along a quick note of thanks for your consistent (and consistently useful) answers to the many questions posted. Reading all of the questions, along with your thoughtful answers, provides an excellent overview of the 180 approach. Also, I appreciate your insights about many small details within the questions (such as your thoughts about tapering, or jump-roping, or speed work). Providing these details is a great way for a newcomer to get started, to anticipate challenges, and to make progress. Thanks again. Keep up the great work.

  • Stephanie Thompson says:

    I’m very interested in and intrigued by the MAF method. I am an ironman training for a third half ironman. I want to apply the MAF method to my training but have a question. When can I apply anaerobic efforts such as tempo runs or intervals?


    • Stephanie:

      Generally speaking, people do best when anaerobic work is 20% of their total athletic output. For a lot of people with packed race schedules (this goes particularly for endurance athletes), you almost never need anaerobic training—the racing itself is usually more than enough anaerobic training. This was the case for Mark Allen, for example.

      Also, note that a 10K is already an overwhelmingly aerobic effort. Half-marathons and beyond are almost absolutely aerobic. (Which is why, despite being only half the distance, half-marathons are usually only run a couple of minutes faster than the 13.1 mile mark at the marathon). So, you’ll do far better for your race performance in an ironman or half-iron to focus overwhelmingly on developing your aerobic system, rather than your anaerobic one. For perspective, a recent study showed that in high-intensity intervals, well-trained runners and recreational runners burned very similar amounts of carbohydrates. The increased athletic output (speed) of the well-trained runners over the recreational runners was due to the fact that the well-trained runners burned three times more fat during the interval session.

      In other words, even though it’s important to develop muscle power in order to produce a greater athletic output, the body’s ability to generate that athletic output, particularly when you’re talking about sustained athletic output, lies with the aerobic system, not the anaerobic system.

  • Mike says:

    I am taking two long term meds, one for mild hypothyroidism (synthroid) and two pills for enlarged prostate (avodart, flomax), which with the meds is normal size. I am sixty and I have been using the MAF formula for several months with success (at 120 HR). For some reason it did not occur to me to subtract 10 for the conditions. Is that something I absolutely need to do? Just FYI, my resting HR is 51 and I am currently producing about 465kj for a 45 minute indoor bike ride (avg 173 watts) with 118 HR average.

    • Mike:

      Absolutely. The question is what amount of that wattage is produced anaerobically and what amount is produced aerobically. I’m extremely good at pushing myself. I could run a 5:35 minute mile, and a 1:29 half marathon. But I was trashing my body. Incidentally, I stopped before I seriously hurt myself. Aerobically, it turns out, I can only manage 8:55 minute miles, and that’s after a month of MAF training.

      If you don’t have the aerobic system necessary to sustain that anaerobic output (and recover from it properly), you’re playing a slow and invisible game of jenga.

      The trick is to do your easy training at the MAF heart rate: that should be about 80% of your total athletic output. The rest of the time, go hard. Just keep an eye on your MAF tests. If your MAF speed starts slowing, then first reduce the amount of anaerobic training, and then reduce the amount of time training.

      • Mike says:

        Ivan are you saying that “the question is what amount of that wattage is produced anaerobically and what amount is produced aerobically” because I did not subtract 10 for the meds? Because if you aren’t then it’s all in the MAF zone. I never go over 120 (I mean it might accidentally hit 120 for a second or two but I immediately slow down and breathe deeper to get the HR back in the zone). Also when you say you stopped before you seriously hurt yourself, what sort of serious hurt are you talking about?

        • Mike:

          Yes. I apologize for the lack of clarity. Basically, adding meds gears your present hormone balance towards ameliorating a particular illness or problem. (Generally speaking, you can make this claim with just about all meds). When you exercise, your body has to create a very particular combination of hormones, in order to create proper functioning across all its systems. When there are meds altering your body’s hormonal situation, the effects of the normal hormones you produce during exercise can (and typically do) have effects that your body wasn’t accounting for. Typically, this is a stressor. In almost every case (99.99%), stress creates anaerobic function. That’s why it’s important to play it safe and reduce the heart rate a little, to reduce the chance of anaerobic function.

          About seriously hurt, I mean I was going all the way. I used the first two miles of my training runs to numb my shin splints before I started picking up speed. I had constant colds and severe allergies. I was exhausted most of the time. I broke my left navicular bone once, and started running as soon as it healed enough that the pain became bearable. Even now my 3rd met on my left foot sticks out when I flex my toes. You name it, I did it.

          I probably read a little too much Born to Run for my own good.

          But I got real with myself and told myself that running shouldn’t be this way, even if it is for the overwhelming majority of people. 5 years of personal research later, and I’m working with Dr. Maffetone, my muscle imbalances are almost gone and steadily developing aerobic competency. And even doing 40, 50 mile weeks with 2 hours of floor training (flexibility, body weight, and kettlebells) 5 days a week, running with pain is nothing more than an unpleasant memory.

  • Rudy says:

    I have been running at MAH for 45 minutes 4 days (in a row) a week and rowing once a week now for 3 weeks.

    I have just signed up for a 10 mile trail race on Nov. 29th.

    What would be your recommendation, in modifying my current training routine in preparation for this race?

    Thank you in advance!

  • Jim says:

    Just a quick note to say how much I appreciate your responses. I’ve read the whole blog and have really learned a ton about training which I am applying.
    Keep up the good work.

  • Ben Zimmerman says:

    I am 15 years old and I just started with the Maffetone method, although I have been doing aerobic training for quite some time. I have noticed that the 180 formula puts me at a higher heart rate, (165 versus 158), than most other methods. I just went on a 9 mile run and I found that running just below 165 heart rate was quite stressful. It felt more like moderate to hard intensity than easy. My average pace was around 8:30 per mile. Do you recommend that I keep running at this heart rate or slow down?

    • Ben:

      The MAF heart rate is when your aerobic system will develop the fastest. Although lower heart rates are also “aerobic,” they’ll just mean that your aerobic system takes longer to develop. What I would do is run at the MAF heart rate, and do MAF tests every 2 weeks to keep track of your aerobic speed. As long as you continue to see steady improvements, you’re on the right track. If not scale back on the volume of training: first reduce anaerobic training, and then reduce the time training.

  • Ben Zimmerman says:

    I am a 15 year old runner that just began using the 180 formula. I noticed that the aerobic heart rate you recommend is higher than the aerobic heart rate of other calculators. 148 to 158 beats versus 165 beats. The other day when I went on a 9 mile run I noticed that the intensity felt like moderate to hard effort compared to easy. My pace was around 8:30 per mile. I have done other aerobic training in the past, but this felt a harder than I expected. Should I keep running at this intensity, or try a different heart rate.

    • Ben:

      The 180-Formula tells you the maximum heart rate at which your aerobic system gets activated with minimal anaerobic function. So, while lower heart rates are also “aerobic,” this heart rate will make your aerobic system develop comparatively faster. It’s not as important to run at “less intensity,” than to scale back the time spent training, if this adds up to too much stress. And the best way to know that is to do MAF tests every 2 weeks or so: if your MAF speed plateaus for more than 4 tests or begins to drop (with no change in weather conditions), it’s time to reduce your amount of total training.

  • Lp says:

    Is birth control a medication that would require subtracting 10 points?

  • A.C. says:

    I’m going to go out on a limb here and assume that birth control counts as medication. Is that right? There are a lot of different kinds, with different amounts of hormones (IUDs have less than pills, which have less than the shot…). Is there a good, general way to account for birth control? Thanks.

    • A.C. You’re right. For now, just remove the 5. I’ll discuss this with Dr. Maffetone and see if we need more specifics.

      • Ketorunner says:

        Dear Ivan,

        First of all I would like to say thank you for answering so many great questions. I have read most of the posts and it has really helped me to understand MAF much better.

        I am 59 years old and have been running for a long time. 6 months ago I started a LCHF (Low Carb high Fat) diet. I won”t go into detail, but I will just say that the health benefits and my running ability have improved beyond anything I expected.

        I am currently training for a marathon that will take place in October and would like to do one more LSD run. My question is: Based on my MAF heart rate of 180 – 59 = 121 + 5 =126, I average 10 minute miles. I want to do at least 18 miles, but that means I will be on my feet for at least 3 hours. I have a feeling that may turn out to be a case of diminishing returns. Any advice?

        Thank you

        • Ketorunner:

          Thanks for commenting. Although you will get diminishing returns in terms of training, the benefit that a long run has to an endurance race such as a marathon is enormous: gaining a psychological comfort for being on your feet for a long time is as important as training the body for the actual event. So, go ahead.

      • A.C. says:

        Thanks for the response. Did you mean that I should subtract 10 for the birth control as medication? (your commend said to subtract 5).


  • Stephanie Jamrog says:


    I am an endurance runner and am starting an off-season block of training in which I hope to burn fat and build up my aerobic base with the Maffetone Method. Every morning, I take my dog for a quick 30 minute run so he can get some exercise and just because its a nice way to start the day. I usually push the pace during these runs since they are so short; my endurance training runs occur after work and on weekends. But now that I am trying Maffetone, I am wondering – is it still beneficial to train within my aerobic threshold, even if for only 30 minutes?

  • Sugandhi says:

    I have been running for last 2 years and have done 4 half marathons at 7 min/km. My average heart rate during all runs stays in high 160s and early 170s. Resting heart rate is late 50s/early 60s. I am 39, so my MAF should be 141+5 =146.
    If I were to train using this method it would mean doing at least 9-10 min/km which would be too slow. I am training for a few halfs in next couple of months and cannot afford to reduce my speed too drastically.
    Any suggestions.

    • Sughandi:

      I’m not sure what kind of suggestion you’d like. We suggest indeed keeping your heart rate at MAF for 80% of your total athletic activity, with 20% anaerobic training. In our experience, this affords people a much greater training volume and much safer athletic development. There’s plenty of studies (not to mention plenty of famous coaches) taking these more measured approaches. I can provide you sources if you’d like.

  • Mike Wernert says:


    In reference to your response to Sugandhi’s comment, I would love for you to provide me with sources for the comments you left. I am an Exercise Physiologist and am passionately interested in pursuing this information further.

    Kind Regards,

    • Mike:

      My response to Sugandhi was an oversimplification of the 80/20 rule found in a lot of lay and scientific sports literature. Off the top of my head, the study to best describe the benefits of going more aerobic (read: low-intensity) for an overwhelming percentage of training are described by this study:

      Esteve-Lanao J, Foster C, Seiler S, Lucia A. Impact of Training Intensity Distribution on Performance of Endurance Athletes. Journal of Strength and Conditioning Research. 2007;21(3):943-949. doi:10.1519/00124278-200708000-00048.

      There’s little question that large amounts of high intensity training (HIT) develop performance indicators (strength, speed) more quickly in the short term, than does medium and low intensity training. However, the ratio 80 med/low : 20 high intensity is born from the observation that sustained, high volume HIT has negative health effects in the long term resulting from the increases in activation of the HPA axis (and release of hormones including but not limited to cortisol, adrenaline, and GH) that make short-duration HIT so beneficial.

      Generally speaking, due to this we (and others) believe that sustained HIT puts the body in a state of prolonged acute stress. The body sacrifices long-term health to produce short-term performance gains—a case of trying to adapt to an acute stressor (exercise) without chance of recovery from the stress.

      • Mike says:

        Interesting, and thank you for the reply Ivan.

        So out of curiosity, when an individual pursues HIT for a prolonged period of time and reaches the point of stage 1 or particularly stage 2 of overtraining syndrome (as defined in the article), is it possible to pursue training in the form of the 180-age MAF method to reverse some of the long term sympathetic over-stimulation/HPA-axis shifts that are a result of chronic overtraining?

        I have a few clients that I work with who regularly (6+ days/week) partake in HIT training in the form of anaerobic intervals, and they are most certainly displaying signs of overtraining. They are very familiar with heart-rate training, which is good.

        I guess my question is: could they switch their training to adhere to the 180-age to reverse overtraining? If so, what would you recommend as a timeline for doing so (Frequency, Volume)?

        Thank you so much for your time. The information on this site is phenomenal.

        • Mike:

          Thanks for your continued interest.

          Generally speaking, stage 1 of overtraining is dangerous, but stage 2 should really be seen and understood as a medical condition. Stage 1, the sympathetic nervous system (SNS) is overactive. They’re hyper, and the SNS is getting stressed. Time to cut down on training. But stage 2 is really a very severe physiological malfunction. The SNS is so tired that the body has to use the PNS, which generally puts the body in “rest mode” to produce the functions that the SNS usually does.

          This may be one of the reasons that the symptoms of OTS are so broad and unpredictable: when the PNS takes over an exhausted SNS, it’s the physiological weak link (whatever it is) that becomes symptomatic: that could be their nervous system, their circulatory system, their immune system, you name it.

          The point being this: to pursue a high level of aerobic function (MAF) you need a pretty high level of SNS function. When in stage 2 (parasympathetic) OTS, training at MAF would further exhaust their SNS, and catapult them even further into overtraining. What they really need at stage 2 is rest, rest, and rest, and once they can manage it, very low-level aerobic activity such as walking.

          But in stage 1 OTS, when the problem is overactivity of the SNS, exclusive MAF training done correctly should balance out SNS/PNS function.

          The timeline that I would suggest for people in Stage 1 OTS is 3-6 months (depending on the severity) not just of exclusive MAF training, but of continued improvement in their monthly MAF test. In other words, you want to make sure that not only they have been training aerobically, but that their aerobic base is improving for 3-6 months.


          Because there could be a variety of other stressors that contributed to their OTS in the first place: workplace stress, death of a relative, bad nutrition, chronic inflammation, etc. If these stressors are not removed, the aerobic system will not be in a position to function correctly, and therefore won’t really develop. That’s one of the secrets hidden in plain sight: There’s a point to MAF being “Maximum Aerobic Function” and not just “Maximum Aerobic Capability” or something: it’s really aerobic function that does the trick, not just the rehearsal of an activity that should theoretically be aerobic but isn’t because of stressor X or Y.

          To recap (and some additions):

          3-6 months of exclusive MAF training and improvement at the MAF test
          5 days a week; 2 days of rest

          Generally, I would start with 15 minutes of MAF training bookended by 15 min warm-up and 15 min cool-down, going from 25 BPM below MAF to MAF (WU), and from MAF back to 25 BPM below (CD). I would be conservative, and try this for a week. If they can tolerate it and their stress levels don’t increase (you might want to track RHR for this) I would add a few minutes at MAF (5,10, or 15), whatever is prudent.

          I hope this helps. Please don’t hesitate to inquire with further questions.

  • Howie says:

    As we know, different sets of muscles are used on the bike compared to the run. It’s my understanding that the amount of fast and slow twitch muscle fibres vary in muscle groups. Doesn’t this mean that LT will vary dependent upon muscle group used?

    As an example, my LT for run is 152, whereas for bike it’s 121. (FYI, my biking muscles are poorly trained.) Wouldn’t I therefore expect my MAF maxHR to be lower on the bike than run?


    • Howie:

      That’s right: LT does change depending on the sport. But the MAF heart rate tells you your relative metabolic output, not the particular muscle’s ability to buffer lactate (the limit of which is the LT). So, for an overwhelming amount of people (really, everyone Dr. Maffetone has looked at) the MAF heart rate does not change with sport.

      The reason LT is lower for biking relative to running is that you use relatively fewer muscle groups for biking: in running you only have 1 point of support when you have any, so stabilizing the body over that support has a much greater metabolic cost than for biking, where your weight is distributed across 5 points of support (seat, handlebars, and pedals).

      This means that the body can pour relatively more of its metabolic energy into far fewer muscles for biking than it needs to for running. This means that a cyclist’s leg muscles can reach their LT at a lower metabolic output than a runner’s muscles: the runner’s same metabolic output is feeding a lot more muscles, each of which needs to reach their own specific LT. You need a far higher metabolic output (meaning a far higher heart rate) to achieve that.

      The problem is that at heart rates higher than MAF, energy needs outpace both (1) the breakdown and use of fats for energy and (2) the intake and transport of oxygen, meaning that the body has no choice but to engage anaerobic channels—not of a particular muscle to fuel that particular muscle, but of the muscles across the body as a whole, in order to feed the metabolism’s additional energy needs.

      • Howie says:

        “…the MAF heart rate tells you your relative metabolic output. …the body can pour relatively more of its metabolic energy into far fewer muscles for biking than it needs to for running. This means that a cyclist’s leg muscles can reach their LT at a lower metabolic output than a runner’s muscles”

        Thanks for the clarity between MAF HR and LT!

        Further questions:
        1) In those cases when LTHR is significantly below MAF HR which one do I want to use to ensure training occurs aerobically? It seems odd that while biking I’d chose the MAF HR since the leg muscles would be anaerobic by the time I got within 15 beats of the lower end of my MAF training zone–even though the body’s metabolic system would still be aerobic.

        2) For cycling, will my LTHR rise as the cycling muscles become stronger? If yes, is it because they are stronger and/or that they are more efficient? If no, please explain why not?


        • Howie: Sorry for taking so long to answer.

          1) Your situation is an uncommon one, but not unheard of. Typically, you’d want to train at your LTHR until you get to MAF, and then train at MAF.

          2) The LTHR will indeed rise. As you train, particularly if you are under your MAF heart rate, your muscles will develop more mitochondria (which are the engines that process glucose and fats in the presence of oxygen) which means that 2 things will happen (1) you won’t have to process as much glucose anaerobically (which produces lactate), and that lactate you produce will get processed faster through the mitochondria, meaning that it will take a relatively higher metabolic output for the lactate to start accumulating (LT is the onset of lactate accumulation).

    • simon says:

      That’s very helpful to me, I’m currently needing to reverse overtraining from weights/intervals – I’ve been having sleep problems intermittently for 3-4 years now. I think this means high cortisol ie. SNS OTS, so if I understand correctly I should be good to start MAF training immediately. I have a couple of questions about that:

      1. Should I subtract 5 or 10 from the 180 formula?
      2. Should I decrease carbs? And if so how should I go about it? Right now I eat quite a lot of rice (about half my meal by volume) as I’ve found this improves my sleep. I’m worried if I cut carbs out (for the two week test) this will spike my cortisol again. I’ve done low carb in the past but have found I feel better with more carbs – but is this because I am overtrained?
      3. For reversing OTS I understand I should avoid ALL anaerobic efforts – can I still do some weights so long as my HR stays below my MAF HR, or would it be better to avoid altogether? I quite like greasing the groove with sets of pushups, squats etc thru the day.

      Thanks very much for any comments you can make, and for all the responses you’ve already made – this must take time and is much appreciated.

      • Simon:

        Let me answer your questions in order:

        1. Remove 10 beats for OTS.

        2. I would suggest reading the Two-Week Test article to see if you have symptoms of carbohydrate intolerance (difficulty sleeping is one of them), and consider taking the test.

        3. Bodyweight is fine under the MAF HR, but anything that requires a lot of torque (such as squatting with weights) will constitute an anaerobic effort regardless of your heart rate. For example, I tell people that a split squat, single-leg deadlift, or turkish get-up loaded with 10-15 lbs counts as aerobic for most people.

  • Vitalij says:

    b) If you are injured, have regressed in training or competition, get more than two colds or bouts of flu per year, have allergies or asthma, or if you have been inconsistent or are just getting back into training, subtract an additional 5.

    Living in Nordic county its impossible not to get more that two colds per year. I don’t think its related to over-training in any way. Should i still subtract 5 if i i’m training consistently for years, run marathons and never had any injury. Just multiple colds/flu when weather becomes really bad (never get colds in summer)

    • Vitalij:

      I strongly urge you to reconsider this statement: “Living in Nordic county its impossible not to get more that two colds per year. I don’t think its related to over-training in any way.”

      Getting constant colds (yes, more than 2 colds per year is considered constant) means that there is an underlying systemic issue with your respiratory system. If you get more than 2 colds per year, it means that your respiratory system is under constant stress—and breaks down because of it more than twice a year. Because one of the pillars of the aerobic system is the respiratory system, this means that the aerobic system is weaker than it could be, and therefore doesn’t hold up to that much stress.

      Respiratory stress is absolutely related to overtraining—the greater the respiratory stress, the greater the chronic anaerobic function for 2 reasons: (1) stress itself creates anaerobic function (a big way chronic stress makes people sick is due to excess acidic hydrogen ions created by constant anaerobic function), and (2) a malfunctioning respiratory system means that when forced to exercise, the body has no choice but to rely on more anaerobic function (since there is a lower availability of oxygen).

      Those multiple colds/flu are definitely tipping the balance towards overtraining. Whether or not overtraining happens anytime soon (or at all) has to do with how far that scale can still go before it tips completely. Answering that is tough. But one thing is certain: by not subtracting those 5 beats, you’re not playing the odds.

      Are you sure you want to make that bet?

    • simon says:

      great, I’ll try the 2 week test and subtract 10. Thanks very much, this gives me a game plan, until I found this site I was thinking I was going to have to quit exercising altogether. Very much appreciated.

  • Eliane says:

    my MAF rate is 120, but the problem is that, at this rate, I only can walk (fast) but not run anymore, immediately after starting to run it goes up to 135/145. Should I go on walking then until it I am able to run with 120? And how long would it take?

    • Eliane:

      It really depends how long it takes people. Remember that MAF training really is more than endurance training—you’re developing your aerobic base. This distinction is important because the aerobic base is responsible for the body’s upkeep. If there are muscles or areas of the body that have been neglected due to a lack of aerobic power, or health problems, you are typically going to see those resolved before gaining a lot of aerobic speed.

      Another issue to consider is the shock absorption component of running: stabilizing the leg in order to land from a running step takes a lot of metabolic power, which you don’t really need during walking. One of the best ways to “bridge” running and walking is jumping rope (at MAF HR), which is just like running in the sense that you’re absorbing shock but different in the sense that you aren’t moving forward.

      Judging by where you are at, it would probably take 3 months or so. (Because of the metabolic cost I mentioned above, it takes a greater aerobic increase to go from walking to running than to go from running speed A to running speed A+1).

    • simon says:

      Sorry, one more question: how long should I work at the “subtract 10” level? Until my MAF test plateaus?

      • Simon:

        Not quite. It depends for everyone. For example, if you have arrhythmias (which counts as a serious illness), you would subtract 10 until a relevant professional says that the arrhythmias are gone. For example, since I have a problematic muscle imbalance in my hip, I subtract 5 even though I’ve been training consistently for about 6 months now.

        When you can say in good faith that the problem is gone, add those beats back in.

        • simon says:

          Great, thanks very much. This is all very new to me (I’ve been very anaerobic until now – hence the overtraining!) so I’ve ordered the Big Book of Health and Fitness – I’m looking foward to trying out and learning from this way of training.

  • Mark Robinson says:

    Hi – a little advice on MAF HR please.

    I’m a relatively fit 53 year old and I am 3-weeks into using the MAF technique for running (am trying to adopt the dietary side too with less success so far! I gave up running 3 years ago due to multiple recurring leg injuries and now cycle/spin regularly but have started to run again using your technique and so far, so good – no injuries to report and I am running at c7.5km per mile to achieve an average HR below my MAF with at least 60% of the elapsed time being below my MAF HR.

    My MAF HR should be 127 (180-53) and I’ve been using that. I know, however, that my Max HR is 188 (220-32) so much higher than the usual simple calculation for Max HR. This means my MAF HR is calculated at only 67% of Max HR. Should I still use the 180-age for MAF HR or should I increase my MAF HR to take account of my higher max HR? Hope this makes sense…thanks.

  • Michael says:

    Hi on the formula. I am currently on regular medication – risperidone for my mental health. I have been running for over 3 years . Did let fitness go a little bit at end of last year but kept running. Would I still have’t to take -10 away from my heart rate as well as my age as this would be 130 and I would be crawling. I can tip away quite nicely at 138 bpm. Any advice much appreciated.

    • Michael:

      In your words, how long would you say you have been “back at it”?

      • Michael says:

        Tried to respond to this thread but it keeps popping up as new thread . Please see below question – response and next response. Cheers – Bought big book of endurance interesting read so far.

        October 11, 2015 at 10:09 am
        Hi on the formula. I am currently on regular medication – risperidone for my mental health. I have been running for over 3 years . Did let fitness go a little bit at end of last year but kept running. Would I still have’t to take -10 away from my heart rate as well as my age as this would be 130 and I would be crawling. I can tip away quite nicely at 138 bpm. Any advice much appreciated.

        Ivan Rivera, MAF Editor
        October 12, 2015 at 4:35 pm
        In your words, how long would you say you have been “back at it”?

        October 13, 2015 at 7:28 pm
        Not sure if this registered as reply to your question first time.
        Been training seriously since start of year did marathon in June and have been training for another at the end of October. Cheers

        • Michael:

          Sorry about that. I’d say that you do need to take away the 10 BPM. Always be conservative with the 180-Formula.

          The reason for that is because any medication changes the behavior of the nervous and hormonal system (for example, the hypothalamus, which is a part of the brain, controls the main channels of the hormonal system). Both hormonal system-specific and nervous system-specific hormones change the behavior of both systems.

          The aerobic system needs a very particular hormonal mixture to burn fats correctly, and so the mixture of medication and physiological stress (from a higher heart rate) can throw off the ability of your body to break down fats.

  • Slim934 says:


    There is quite a lot of informaiton on how it takes to build the base and what parameters one needs to look for.

    My question is: how do those parameters fit into workout programming?

    Example: I’m 29, so my formula would be 180-29 = 151 bpm (I suffer from none of the modifiers mentioned). So I need to reach that bpm, but I do not know how long I need to sustain that bpm per session (ex. 30 minutes at 151 bpm) and what is an appropriate number of sessions in a given week (ex. 3-4 per week). How does one go about determining this information?

    Thanks much for your time.

    • Slim:

      Since the aerobic base sustains athletic gains much like a foundation sustains a house, it’s important to devote quite a bit of time to it. Usually, the best way to structure workouts is as exclusively aerobic and exclusively anaerobic: for example, an aerobic/anaerobic workout (a.k.a. intervals) primarily develops the anaerobic system (and also somewhat develops the aerobic system as a consequence). But you want to set aside time to develop the aerobic system by itself. So you need aerobic-only workouts.

      Generally speaking, you (and by you I mean everyone from Joe Smith to an elite runner) want to spend around 80% of your total athletic activity developing your aerobic base, and 20% training the anaerobic system. Structure your workouts that way.

      The best way to figure out what is the appropriate level of training is to start slow, and slowly build it up. For example, if you can run a mean 5-K (below 20 minutes), start with 5 consecutive days a week. 4 days a week, work out at the MAF heart rate (15 minute sessions) bookended by at least 12 minutes (by which I mean 15 minutes) of active warm-up, and the same time for active cool-down. Then, the 5th day train anaerobically for 15 minutes, also bookended by warm-up and cool-down. Then you rest for 2 consecutive days.

      You want to take your resting heart rate (RHR) the moment you wake up in 4 different instances: (1) before your first aerobic day, (2) at the end of your last aerobic day, (3) at the beginning of the day that follows your anaerobic day, (4) at the end of your 2 consecutive days of rest.

      Your RHR at (1) is your baseline. If (2) is higher than (1), you’re already working out too much. Aerobic days should bring your heart rate down, not up. If this is the case, you have no business going anaerobic. Rest for 2 days and go aerobic for that time again.

      If you decided to do the anaerobic day, your RHR at (3) will probably be higher than (2) that’s fine. It’s also fine if it’s a little higher than (1)

      This is what (4) is for. After those 2 days of rest, your RHR should be at least back to baseline (1). If it is back at baseline, or below, you can increase your athletic activity by 5 minutes the next week, and so on.

      If you’re only a runner, just keep track of your MAF heart rate. If you are doing both aerobic and anaerobic workouts, test yourself every 2 weeks. If you plateau for more than 2 tests or your speed begins to drop, go all aerobic. If your aerobic speed continues to rise, lengthen your workouts OR increase your anaerobic time (but never over 20% of total volume).

    • Michael says:


      Been training seriously since start of year did marathon in June and have been training for another at the end of October. Cheers

    • Michael says:

      Not sure if this registered as reply to your question first time.
      Been training seriously since start of year did marathon in June and have been training for another at the end of October. Cheers

      • Michael:

        Sorry, I didn’t. How long have you been training? I think you could do well with 30-45 minutes of MAF runs 5 days a week, each bookended by 15 minutes of warm up and cool-down. Try that for the first week. If you are stress-free after the first week, consider increasing the time a little bit.

  • Markus says:

    I used the MAF method very successfully for a half iron-man so I know it works well. I go back into bike racing now and need to tweak to fit that sport. The big difference is that in bike racing the efforts are much more dynamic compared to triathlon or even running. It often requires numerous very intense short efforts at or above anaerobic threshold. If you can’t do them you get dropped and your race is over in seconds. I read that you recommend a 80/20% aerobic/anaerobic max. training load which is more anaerobic then I need. What I don’t fully understand is how aerobic training (at MAF HR) influence anaerobic training and vice versa. For example, if we compare 10 hours per week aerobic compare to 10 hours aerobic + 2 hour anaerobic which one of the two will give me a better aerobic capacity? In other words, does the additional anaerobic training a) improve overall aerobic capacity b) leave it the same level c) or take away some of the aerobic capacity. Please explain why. Many thanks.

    • Markius:

      Thanks for commenting. 80/20 is the max anaerobic recommended (and it includes races, which is why I refer to it as “total athletic activity”).

      So, think about the little engines of the aerobic base: the mitochondria. What they do is process sugars and fats aerobically, and break down lactate. The more you train your aerobic base, the more mitochondria you have. So, for efforts that have some anaerobic component to them (whether or not they are above or below the AnT), a bigger aerobic base means 3 things (1) you can process a lot more energy aerobically, (2) that it takes relatively more anaerobic work for lactate to start accumulating, and (3) what lactate does accumulate is eliminated much more quickly.

      So, not only will (1) your efforts at the same power output be more aerobic, but when they are anaerobic, (2) you will be able to sustain them for longer, and (3) you’ll be able to recover from them that much more quickly.

      Anaerobic training doesn’t really increase anaerobic capacity (in interval training, it is the resting period in between intervals that develops the aerobic system). But the reason that most people destroy their aerobic system with interval training isn’t because it doesn’t develop the aerobic system, but rather because the volume that people typically do constitutes too much stress for the body to recover from.

      But another one of the problems with exclusive interval training (such as HIIT) is that the aerobic system is developed only in function of the anaerobic system. In other words, the only reason you give your body to develop its aerobic base is to be able to recover from an anaerobic workout. So you perennially exist in a situation where the development of the anaerobic system outpaces the power of the aerobic system, and the aerobic system has to struggle to catch up.

      At MAF we refer to this as a “problem.”

      Your aerobic base will always be “absorbing” your anaerobic training. Every time that you train anaerobically, those mitochondria will be worn down in order to process that lactate. So, very little anaerobic training will help you develop a robust aerobic base, but you also want to develop your aerobic base to a level where it can absorb what anaerobic training you do throw at it (because you do want to develop power, and power is important).

      The point is, insofar as your aerobic base can absorb the anaerobic training that you throw at it (and recover from it properly), no, anaerobic training will not reduce your aerobic capacity. An 80/20 or 85/15 rule works well with most people, provided they are not ill, injured, overtrained, recovering, expressly in an aerobic base building cycle, or just starting to become active.

  • Cristina Wood says:

    Hi there. My question is, how long do we workout at our aerobic heart rate? 30 mins? One hour?

    • Cristina:

      I can’t say. An elite marathoner’s off day would be one hour of easy running. Someone with no prior athletic experience may have a hard time getting to the MAF heart rate.

      It all depends on your athletic history. Can you say more?

  • kontxi says:

    Hello, Ivan!
    I am a runner who likes to run quiet on the beach and mountains. 15 years I’ve been running and occasionally I run a half marathon, and in April ran my first half marathon mountain. Despite saying I like run quiet, seeing my current pace I realize much in anaerobic running. Now I realize how I forced my body to run almost without oxygen.
    I am on day 10 of the trial two weeks. And I have several questions.
    1- It is normal to have to go slower and slower? That is, at first days I could jog, but yesterday and today I have to go walking much of the time. It may be for not taking no carbohydrates in these 10 days?
    2- I am also tired. It is normal for the TWT? In 10 days I’ve gone from 54kg to 51.5. I may be losing too much weight? That’s not my intention, weight loss, just wanted to improve my aerobic capacity. Until now I eat a vegetarian diet and during this two weeks I have included eggs, fish and some meat, but especially many nuts and vegetables.
    3- So far I had not read about heating and cooling. Just I put me to run my 140 beats. If I run 45 minutes in the morning, it would be sufficient to heat 7′ at 120, running 30´ to 140, and other cool 7´-120, or really have to do heating and cooling 15 minutes?
    4. I know it’s soon to run a marathon two and half months after starting the test, but will be detrimental to, since the BMP for marathon you says must be 10-15 over your MAF.
    5. The MAF test is successful do it with kilometers instead of miles?

    Thank you very much for this wonderful place expansion of knowledge!

    • Kontxi:

      Thanks for your continued comments here on the site. Let me answer your questions in order:

      1) Yes and yes. Your aerobic system has 2 main parts: your fat-breakdown and fat-burning capability, and your aerobic sugar-burning capability. So by removing sugars and carbs from your diet, you are meeting the actual fat-burning ability of your body. Exposing this so that you can explicitly train it is absolutely crucial. For example, I do 2/day workouts for this very reason: in the morning I work on stability, mobility, and strength, which largely deplete my sugar resources (but I watch my stress levels very closely) and in the evening I run at my MAF heart rate, in which I am basically forced to utilize fats for fuel. Yes, I am slower, but the training is a lot more targeted (and in the long-term, a lot more effective) than otherwise.

      I wouldn’t recommend doing it my way just because you need a lot of organization, not to mention knowledge, to pull it off without eating away at your aerobic base.

      2. Weightloss is typical during the two-week test, and it is usually associated with carbohydrate intolerance. In view of this, it is no surprise that you lose a lot of speed during the TWT. What’s basically happening is that by being forced to rely on fat for fuel, you are losing weight. It’s highly unlikely that you’re losing anything you don’t need. Whether this weightloss is unhealthy, ask yourself whether your body is functioning better or worse. If it is functioning better, by definition you are approaching a better weight for you.

      3. I like to stress the importance of warming up and cooling down. I literally spend 1 full hour, every day, on this (15 minutes of warm-up and cool-down for each of my 2 workouts). I really do believe it’s that important. I like to tell people that the 4 components of training (warm-up, workout, cool-down, and recovery) are like the 4 parts of the day: sunrise, midday, sunset, and night. The reason I use this metaphor is to stress in the strongest terms that the quality of your workout depends on the quality of your warm-up, and the quality of your recovery depends on the quality of your cool-down. (You can’t get to midday without going through sunrise, and you can’t get to night without going through sunset).

      Many, many important things happen during the warm-up and cool down. The most important is that during the warm-up, your body slowly shunts blood out of your organs and towards your muscles, and all the capillary networks that feed your muscles have a chance to properly dilate. You really need 15 minutes for this to happen—the chemicals that dilate the capillary networks (CO2 and O2) are tied to the same hormones that promote fat-burning. Furthermore, just kicking up your activity level quickly is a very stressful endeavor—in the wild, you would only do that if there was a predator on your tail. So by not giving your body the appropriate time to warm up, that’s exactly what you’re telling it is happening. You’re giving it a hell of a reason to start working anaerobically.

      Similarly, if you stop activity without cooling down, your heart rate will just drop, and all the blood that you put into your muscles won’t have a chance to come out—meaning that your organs will have less blood afterward, blood will stagnate in your muscles, and all the by-products of exercise that are still in that blood won’t be quickly recycled through the relevant organs.

      Like I said, the more time you give to these processes, the better exercise and recovery you’ll have.

      4. The point of developing an aerobic base is to meet the challenges of life, whether they be challenges that we set ourselves (athletic events) or challenges that we come upon (a lion in the wild). Yes, a marathon will decimate any aerobic base that isn’t capable of meeting that colossal a challenge. That’s the point. I like to say that there’s a damn good reason that the marathon is the closing event of the Olympic games: of all the events, it poses the greatest physiological challenge to the human organism. When your body experiences catastrophic, systemic failure at a power event (i.e. weightlifting), you break a joint. When your body experiences catastrophic, systemic failure at an endurance event, you die.

      Now, if you ask me straight up “should I do a marathon?” this is my answer: Not knowing you or your athletic situation, the marathon must be earned with 10 years of reasonably continuous aerobic athletic development. The marathon is the closing event of the Olympics.

      While I can “run” a marathon, I’m not really physiologically capable—yet—so I don’t. (Even though I previously did run a 3:17 marathon). I’d say that for 90% of the people that you see running a marathon, doing so is folly. Heart attacks, respiratory illnesses, heat exhaustion. These are indicators that the challenge was overwhelmingly greater than the organism’s capabilities. Most competitive athletes “earn” the marathon in 20 years of running. Think about that.

      5. Yes. You can do the MAF test with kilometers, as long as you’re consistent with your measurement of choice.

      I truly hope this helps. I hope I haven’t put you off by my rant about the marathon, but I do think that it’s very important for people’s athletic well-being (and their athletic future) to come out and say this. Of course, you know yourself best. The marathon defeats many people: their first can be their last. With 5 or 10 years of diligent training, those very same people could have run 100.

      • Kontxi says:

        Hello again, Ivan !! Your metaphor dawn, noon, evening and night is with me since yesterday, and today, the eleventh day, the first time I could run, speed grandmother, both during heating and during the following 30 minutes, without forgetting cooling. And I think that warming of 15 minutes has made the difference. Thank you, thank you, and thank you … and after consultation with the pillow and my partner, we decided to run the marathon…. next year … :))

  • Eric L. says:

    I started HR training in April 2015 in preparation for a half iron-man in Late October 2015, under professional medical care. It was a real struggle to slow down to a 10:45/11 min pace on a 5k where I had to walk to get my HR back down. After 6 months, I’m cruising along at 9:30 pace for 13 mile runs with a max HR of 142 or so. It’s not my lungs that stop me – #shutuplegs shoutout to @thejensie
    In September, I dropped the hammer and really pushed my 5k time down to a sub-21 minute ( faster than I was in HS, over 25 years ago).
    Earlier this month, I ran 8:37 pace for 10k at an avg HR 136, max 148.
    Race day is less than 10 days, and I’m excited to see what happens when I put it all together.
    I can literally feel the increased lung capacity on a daily basis. I’m a huge fan.

    • Eric:

      Glad to hear about your successes! Keep them coming!

    • kontxi says:

      Thank you very much for your extensive answer. Who knows! your advice may be vital in my life. After making the mountain half marathon, 21 km, with an accumulated 2,700 meters altitude, I thought a marathon could be the next step. I thought I could not be tougher. Although perhaps we may need to change that mindset hard, and start enjoying more, with more oxygen in our bodies … I’ll observing the coming weeks, and we’ll decide whether to terminate or postpone my Olympic games. Thanks again!!!

      • Kontxi:

        It’s always best to be conservative, and to not play fast and loose with our health and athletic future, but who knows, after a well-executed mountain half-marathon, you may be ready for a marathon with a few months of event-specific training! It’s not about being afraid of the marathon, but rather about knowing what challenges you can and cannot presently meet.

  • Alicia says:

    Good morning!
    I’ve never run with a HRM before and after hearing feedback from my running friends and the forum, I expected to have to slow down considerably, but this is not what happened.

    I’m 35, so my target HR should be 180-35+5 = 150, resting HR 49. I ran 4 miles at the marathon pace (7.30) and could hardly get it to hit 140 bmp. When I slow down to about 8.30 min pace, my heart rate stays about the same (138), but when I stop it drops to 124, 123 etc by the second and reached 90s in about a minute.

    Obviously, I can’t do all my training at faster than the marathon pace but would really like to leverage this method. Any suggestions?

    • Alicia:

      Could you tell me a little bit about your athletic history? Training, racing?

      • Alicia says:

        Hi Ivan, sure:
        I’ve been racing for the last 15 years, half marathon PR 1:30, Marathon 3:20, 10 miles 1:07, 5K 19.50

        Currently my training pace for long runs is about 8:45 and the latest marathon time was 3:29 in April 2015. I haven’t been doing any speed work since then, but when I do, I run 3-4 1 mile repeats at 6.40-7 min pace and 800s at 3-3.10 min pace. It feel like a pretty hard effort.

        I did a simulation of VO2Max test on a treadmill earlier this year. Ran on a treadmill at 17% incline and it took me about 15 minutes to get to 164 bmp. I felt I couldn’t push it any further (it felt pretty much like all out effort)

        My current training is:

        Monday: swim
        Tuesday: 6 miles at easy-moderate pace (8.30sh)
        Wednesday: 5 miles at 8-8.30 pace
        Thursday: fartleks, hills, stairs or track for 1 hr
        Friday: Off
        Saturday: long run (15-20) at 8.45-9 min pace
        Sunday: easy 10 miles

        For spring 2016 I’m going to focus on improving my times in shorter races and try to qualify for NYC by running 1:34 or faster in a half marathon in march 2016.

        Based on my history and goals, do you think I should be pushing myself to run closer to 150 bmp or target a lower HR at a slower pace?

        Thank you!

        • Alicia:

          I think that the reason you feel like it is a hard effort is because your aerobic base is very well developed on its own, but also very well developed relative to your total muscle power. PE or “perceived effort” is mostly due to how much percentage of your total muscle strength you are using at a given time. When your aerobic base is capable of providing a lot of fuel (relative to the ability of your muscles to consume it), you are using a big percentage of your total muscle strength at any given time.

          My recommendation is to increase your muscle strength. Two things you should try out is to incorporate a plyometric routine into your workouts, and trade some of your longer intervals for shorter ones in the 50-100-200m distance. I would also consider incorporating a lower-body strength routine, such as single-leg deadlifts (great for gait-based strength!) and the deep squat. This sort of training will help you a lot in your change in emphasis towards shorter races.

          That said, I would do my shorter runs at a pace/ heart rate below MAF (which you find comfortable). As your muscle strength and power increases, you should observe that sustaining a higher speed becomes less and less effortful, until you can reach MAF pace with less perceived effort than before. The idea is not to “exert” yourself at MAF, but rather to increase your total strength/power so that your perceived effort at MAF drops.

          However, since you seem to have a decently crowded racing schedule, I’d recommend that you keep all workouts over your MAF heart rate to no more than 15% of your total training volume.

          Have I clarified things for you?

  • Alicia says:

    Thank you for clarifying, Ivan. This sounds like a very accurate description of my state. Sort of like a car with a powerful engine running on under-filled tires o:)

    I’ll definitely follow your advice: strength training, shorter intervals and doing 85% of my runs at below MAF bpm until it gets easier and I can increase my speed at the same bpm and reach the MAF bpm.

    Very excited to have this new game plan!

  • Alex Hunt says:

    I am a 65 years old guy who has been doing moderate strength training for the last two years. I purchased a HRM and started doing MAF training to build my aerobic base but could not maintain a stable heart rate. After medical testing I have been diagnosed with A Fib.
    Have you got any experience with A Fib or advise on how to train with it? I am not able to do much more than a shuffle without my HR jumping up to 145 or above.

    • Alex:

      The first and most important step is to be cleared for exercise by your cardiologist. Specify to your cardiologist the kind and intensity of exercise that you’ll be doing (and the heart rate you’ll keep). Once you are cleared, start by walking (particularly if this is the only way to stay under the MAF heart rate), and concentrate on breathing. I just answered another comment about how the lungs, when they expand and contract fully, displace a lot of blood, helping the heart maintain blood pressure. (Which means that heart rate can drop a little bit).

  • Sebastian says:

    Dear Ivan,

    I’ve been successfully training the MAF method for the last 3 months. Then suddenly strange thing started happening. A minute after started running my hear rate rises very high (from 110bpm to 170/180 bmp) and keeps like that for about 10 minutes. After that time drops suddenly and looks to be typical. I’ve suspected that my Garmin HRM broke and I’ve bought a Polar HRM. To mu surprise, my new HRM
    shows similar abnormality. The difference is that Garmin apparently presents average values whereas Polar does not do that (of have much shorter time for average calculation) and I can see f.i. 187bpm one second and 140bpm next second. I do of course wet the electrodes or even apply special gel for EKG but it doesn’t help apparently. The only change I can see is that it got colder in my country and I’ve changed my clothes to winter. But the temperature is still above 0 Celsius.
    I honestly say that although I do understand the importance of warm up, I’m not doing it. The reason is that when walking my heart rate is 110 but my MAF training range is 126-135, so it’s only a mater of a minute or two, when my heart rate reaches 135. Then I’ll start my training using the run-walk approach. I’m not using rump rope to warm up since I’m training at 5:00 am and I don’t want to wake my family.

    Could you please advice if it’s at all possible that my heart rate can jump like that. If so what would be your advice. Thank you,


    • Sebastian:

      Your heart rate can jump like that, but you would feel it. You’d go from pretty relaxed to feeling your heart pounding in your chest.

      If you don’t feel any noticeable difference, then your monitor may be mistakenly picking up your heart rate variability (if your average heart rate over 5 seconds is 140, but the latency between heartbeat 1 and 2 is, say .33 seconds, that particular heartbeat, repeated over a minute, would amount to 180 BPM. The other possibility is that your HR monitor isn’t picking up information correctly. A problem may be that there is a barrier between the HRM and the skin (which typically means chest hair). Considering that both your HR monitors are picking up the same thing, proper contact may be the problem.

      • Sebastian says:

        Dear Ivan,

        Thank you a lot for your valuable feedback. I don’t feel like my heart is pounding 180bpm so it must be a transmission error. Today it took much longer (over 20 minutes) until my HR monitor started showing sensible data. The temperature was a bit lower (32F) and I’ve wet the electrodes using water instead of a special gel for EKG. I want you to know that I’m barely sweating during my MAF training and today my whole body was dry after 1 hour running; not a single set spot on my body. I’ve subtracted 5 to come up with my MAF HR as I’m having much more than 2 colds a year. I’m sharing all this information since I would highly appreciate your comment to my question. Will the first phase of my running where I can not relay on my HR monitor, do much harm to my aerobic system development? And another question. You mentioned in this blog that you are working on new formulas to come up with MAF HR. Perhaps it’s a bit too lower for me bearing.

        Thank you,

        • Sebastian:

          We’re also coming out with a couple of devices for people to better measure their aerobic function.

          Generally speaking, you’re not going to very much harm if you just eyeball it. You’re going to develop just fine as long as you stick to the principles: low stress, easy, and lots of aerobic function. Sure, it’s not as good as a HRM (and a HRM isn’t as good as a lab full of scientists), but you can make it work for you just fine.

          You probably know your pace and you probably know kind of how it feels like to run at the MAF HR, so just take it easy, and don’t go too hard. If you get back and you feel tired, sore, or stressed out, you know you pushed a little bit too fast. Don’t sweat it, just correct and try again.

  • Jim Stanton says:

    Hi Ivan,
    Quick question, do know if there is a relationship between the state of ones aerobic system and ones heart rate variability? I’ve measured my HRV for several years and it has never varied much and stayed in a narrow range. Over the last couple of months I’ve been seriously doing strict steady state aerobic training, watching my carbohydrates and my HRV readings have been trending higher, more so than in the past. Wondering if there is a causal connection that you know about?


    • Jim:

      Great question, and I have my own opinion about this. I don’t know whether the causal connection has been studied beyond evidence that says there is one.

      Let me tell you what I think personally. A hallmark (and necessary component) of a great aerobic system is a set of well-functioning lungs, diaphragm, and upper body in general. When the lungs expand, the upper body fills up with air, which means that pressure increases, which means that the blood gets pushed towards the extremities. This means that blood pressure increases, which means that the heart is momentarily partially off the hook for providing blood pressure and for generating circulation, which means that the heart rate can drop momentarily. It has to rise again very quickly to maintain blood pressure during the exhale.

      So, a powerful inhale and a powerful exhale, when framed this way, mean that every heartbeat will happen after a slightly shorter or slightly longer interval than the one before. Hence, increased heart rate variability. And when you don’t have the lungs pushing blood as powerfully, the heart rate has to remain steady throughout.

      To reiterate, this is my opinion.

  • Scott says:

    Great information. So ideally, is it best to stay under the MAF HR by a decent margin? Or should I do my best to “bump up” right next to it while avoiding going over?

    Thanks in advance!

  • Michael Ryan says:


    Just after weeks rest from marathon. Want to try 180 formula for 3-4 months. I am used to going out about 5 times a week. What kind of hours should I be aiming at in a week , For example if I did 15 min warm up half hour running and 15 min cool down, 5 times a week would this be sufficient.

    Also looking to use this method for training for marathon next year is there anywhere I can get a training plan using this method that I could roughly stick to.
    Cheers for any info.

    • Michael:

      I would start with the amount of time (daily or weekly) that you usually train. What you suggest sounds pretty reasonable start. If after a week or two you feel that you can increase your time without increasing your stress levels, try that.

  • Onno says:


    I am really inspired to start using the Maffetone method, but I have a question.

    I have been running for 5 years and I calculated my MAF to be (180-38 = 142). I am a regular runner, no injuries. My running consists of 3-4 runs a week. Do I need to subtract an additional 5 or do I stay with the 142?

    Category b just does not feel right. (not just steeling another 5 beats 🙂 ) But is 3-4 runs a week enough for category c?

    Thanks so much for your reply.


  • Laura says:

    Hi Ivan,

    I wrote in late august (about RHR in regards to MAF HR), checked for a reply and thought perhaps my message hadn’t gone through. Then I forgot to check in again.
    I just now found your reply and wanted to thank you so much! Since Aug. 25, I’ve been on the Maffetone program, (cycling and barefoot running), and LOVE the way I feel after these workouts — so refreshed. I regret how I’ve been hammering myself with HIT training for years, but better to learn later in life than never.
    My nutrition is excellent, but I’m confused as to the timing. I run or ride very early, and read where you recommended drinking coffee to someone who did the same.
    I don’t drink coffee or tea, so should I eat a little something and wait a while, or go on an empty stomach? I’ve read so many conflicting answers from various sites. The last thing we want is to be catabolic. Could you please expand on this topic?
    Thank you so much in advance. What a great site this is!


    • Laura:

      I also do my morning workout on an empty stomach.

      A workout is always going to be a catabolic experience. (“Anabolic workouts” have that name because recovery from them results in increased muscle or bone mass. If you do “anabolic workouts” with no rest for more than 2 weeks, you’ll start to see your body break down.) In order to raise its metabolism above some 1.5 METs, the body has to go catabolic.

      The problem with most endurance runners is that the stress levels remain high enough after exercise that the metabolism doesn’t really come down (so that recovery never happens), so that the body never has a chance to switch gears from catabolism into anabolism. That said, the anabolism that occurs during recovery from endurance sports typically trims the body down and repairs the systems necessary for another bout of endurance. So, while recovery from an endurance activity is still anabolic, it is so in a less obvious way.

      The first way to fix the stress problem, of course, is to train overwhelmingly at MAF.

      The optimal solution is that your morning workout shouldn’t necessitate you eating before it. While eating soon after waking up is important, it’s important because it sets the hormonal makeup for the rest of the day. My morning workouts are never difficult (they perhaps are 10% strength/anaerobic). For example, the fat-burning component of a MAF workout means you are creating the same hormonal pattern than you are trying to create by eating a hearty breakfast soon after waking up. And if you do both together (breakfast soon after the workout, the fat-burning effect becomes compounded).

      This is because the hormone that burns fats—leptin—is the same hormone that produces the feeling of fullness, which you get from a hearty, fatty breakfast. The problem with “not eating” early is that this creates the opposite hormonal makeup: the hormone Ghrelin, which increases both your hunger and your stress levels, becomes released. So the problem isn’t eating or not, but rather which hormones get released, setting the trend for the rest of the day.

      To be able to do a workout in the morning, what I usually do at night is emphasize carbs. Since I can tolerate starches well, for dinner I usually eat a vegetarian chili with lots of garnishes such as avocado, cheese, and sour cream, and some corn tortillas. This is pretty easily digestible (generally speaking but also for me), which means that my muscles and liver are fueled and ready for a morning workout. The fact that I’m fueled also reduces the stress of the workout.

      Summary: I emphasize fats in the morning (think: veggie-bacon-avocado omelet), protein at midday (think: phil’s shake, loaded cobb salad), carbs at night (think: vegetarian chili).

      PRO TIP: soups, stews, etc. are easier to digest since the breakdown of food due to sitting in hot water for a long time means that they have been “pre-digested” so to speak. So they make excellent evening meals.

      Hope this helps.

  • Laura says:


    Thank you for confirming the early morning aerobic workout on an empty stomach.

    Does the fact that I often feel hungry at 4:00 or 5:00 am mean that I’m releasing ghrelin instead of leptin? Can this be altered by
    adding more carbs at dinner? I thought I was getting enough, but maybe not. When I begin the run or ride the hunger subsides,
    and energy levels are good. I typically eat just what you suggested afterwards.
    My strength training workouts are done in the afternoon, about an hour after a small to medium sized meal. Do you believe in
    BCAA”s while lifting, or at all? L-glutamine post workout?
    Do you have an opinion on Bioidentical HRT done trandermally?

    Thank you for your time. Your replies are greatly appreciated,

    • Laura:

      Yes—it does mean that you’re releasing more ghrelin (and less leptin). The nice thing about ghrelin and leptin is that they quite directly create our subjective experiences of hunger and satiety (respectively), so that whenever you get the “munchies”—the sort of “wanting” to eat and gravitating towards food that may or may not be accompanied by a groaning stomach—that’s the ghrelin talking. Also when you get “hangry” (hungry+angry) it’s as a direct consequence of too much ghrelin.

      The fact that there is such a thing as “hangry” is the easiest way to explain the connection between ghrelin and stress hormones.

      What I would do instead of trying to fix the morning ghrelin problem at dinner is by fixing it with the previous morning’s breakfast. Being hungry in the very early morning is one of the aftershocks of having had a disadvantageous hormone cycle the day before. (In my last comment to you I mentioned how the way to set the hormone makeup is by doing things well in the morning.

      So, what I would do in that morning when you wake up hungry is to figure out a minimalist strategy to calm that hunger (and that ghrelin). For example, if a cup of Fat-burning coffee does it for you, that’s excellent. If you need something more, try a handful of macadamia nuts. (which are highest in fats of all nuts). Then go out for your morning MAF workout, and the combination of fats+MAF will already have counted a lot towards the fat-burning hormone makeup you want to set for the day. And when you get back from your workout, even if you’re not hungry, consider having a bit more fat-promoting breakfast: perhaps 1 scrambled egg with veggies and half an avocado.

      If you’re promoting the fat-burning engine like this, what happens? Throughout the day you’ll be burning more fats, which means that you’ll be using comparatively less muscle and liver glycogen to fuel your daily activities, which means that you’ll have comparatively more left over at the end of the day. A small-ish dinner with good low-glycemic carbs should be just enough to top off the tank.

      About transdermal HRT: if you need it, you need it.

      That said, athletes need to be cautious with those kinds of medications because, without specifying which particular hormone therapy you’re talking about, I can tell you that you’re already going to be affecting the basal metabolic rate, muscle mass, bone mass, fat versus sugar burning, etc. Ideally, your hormonal makeup and real-time hormonal fluctuations should reflect the changing demand that exercise, life, etc. place on your body. But when you’re doing HRT, your hormonal makeup and real-time fluctuations are skewed: since HRT puts hormones into your body at a given rate, that rate is never really going to match the changing demands that the real world places on your body.

      This mismatch between the hormonal makeup created by HRT and the hormonal makeup your body would want to have to meet real-time demands, is a stressor. Speaking exclusively about aerobic function, this external hormonal input means that the body can’t change from fat-burning to sugar-burning and back when it wants to, or as easily as it wants to. This is why, in the 180-Formula, Dr. Maffetone indicates that any medication (which includes HRT) makes your MAF HR 5 BPM lower.

      How do you delve deeper into this issue? Consult with a health professional who can study your particular situation and has worked with athletes who need HRT before.

      About various aminoacids during and post-workout: could be useful. The reason I don’t use them is because I could very quickly achieve a degree of exercise where the only thing that stops me from overtraining is a carefully-managed mixture of supplements. (What should stop me from overtraining is a powerful aerobic system, combined with a proper amount of rest).

      So my answer on that regard is: if you’re using them to increase muscle or bone mass (but NOT to be able to maintain a higher exercise volume) then you’re using them well.

  • Tom McCarty says:

    I am 51 years old. So my zone would be 119-129. I set my HRM to beep at 119 and 129. But alot of the time the HRM beeps at 129 and I start walking but my HR can continue to climb above 129 before declining. Is this bad if it climbs above the 129 HR?

    • Tom:

      It isn’t “bad” but it is one of the things you want to minimize. For example, a lot of people set their HRM to beep 2-3 BPM under their MAF HR. To give you an example, when I go out for a MAF run, my average heart rate is usually 3-4 BPM below MAF, and my peak HR is 3-4 BPM above MAF.

  • Fred says:

    I am 35 years old. I have been running for a little over a year. My MAF HR would be 145. Back in April and May, I started training using the MAF method. At first I was doing a 11 min/mile pace at MAF HR but I managed to improve it to a 9 min/mile at MAF HR. I even did a complete half marathon under MAF HR at a little over 9 min/mile. Then this summer I started training for a marathon in September. So I switched my training to speed doing tempos, intervals and long runs. After the marathon I decreased my running volume and switched to long hikes and trail running in October. This past week I decided start training using the MAF method again. To my surprise, I am back to a 11 min/mile at MAF HR and my HR is always peaking. I have to admit that my training in the last 2 months is not what it used to be and I might have gained 5 pounds since this summer, but it seems strange that I would lose so much fitness in such a small amount of time. Have I overtrained prior to my marathon and am I now paying the price ?

  • MojoRisin says:


  • MojoRisin says:

    …also brussels sprouts

  • Nicholas Fosotracer says:

    Greetings (Ivan)!

    I have a question in the interpretation of factor (c). I am 42 years old so can assume my starting point is 138 (180-42). For factor (a) I am also diabetic so would reduce this to 128. None of the factors in (b) are relevant. Now for factor (c), I have been training consistently for 2+ years at least 4x week without any problems mentioned in (b). Does this reset me to 138? I’m guessing that because I have diabetes, I can’t apply the +5 from factor (d) to the 138 (or the 128 if I’m wrong about resetting with (c)). Could you help confirm? I’m lost… Thanks… Nick

    • Nicholas Footracer says:

      Hmmm…nevermind…reading comprehension. Choose the ONE group that best describes, and if fit into two then choose the one that results in the lower HR. I should be 128 (180-42-10). I was training at 133 and that was hard enough…now to go down even further is going to be just a fast walk 🙁

  • Hanna says:

    Hi, I’ve been running for 2 years now and I just discovered your website which confirms what I have been suspecting in my lack of “performance”–that I don’t have a solid aerobic base.
    Prior to finding this website, I already committed to getting into a base training season over the winter, using my turbo trainer instead of running as I can keep a lower heart rate much easier. (I’d be highly embarrased to upload walks to Strava, since I’m already so slow.)
    My MAF would be 139, which would put me right at the beginning of my zone 2 according to Karvonen.
    This article says “all your training” should be in this Heart Rate, but it doesn’t say for how long. I want to race a half-marathon in April, so I would need to incorporate interval and tempo runs end of January. Is that too early or incompatible with the MAF training plan? How would I know how long to do this training for?

    • Hanna:

      When doing aerobic base-building, then yes, all your training should be done in this heart rate. The usual period is 3-6 months. In particular, you should look for 3-6 months of improvement, not just of aerobic training.

      That said, remember that a half-marathon is an overwhelmingly aerobic sport (98% of your energy is processed aerobically). So, spending the majority of your training developing your aerobic system will do far more for your race performance than intervals ever could. Think about it this way: when a couch potato, crossing the street, realizes that they are about to get hit by a car, they fly out of the way. That power isn’t really going to leave your muscles during a period of aerobic training, and half marathon heart rate is only marginally (10-20 BPM) higher than MAF heart rate.

      You should have no problem doing exclusive aerobic training, and, supposing that you had 5 months of improvement, still expect a PB.

  • Jessica says:

    I have a max HR of 210 as a 37 year old female. A resting HR of 53. I have been a distance runner and fitness instructor for quite a few years. I have seen two cardiologist and nothing “wrong” has been found. I have both bradycardia and tachycardia episodes, but there is no cause for them. So my HR can drop to 39 and go up to 128 while “at rest”. When working out/running my HR rushes up very quickly. For conversational run pace my HR sets between 167-183 depending on how far into my run I am (the longer I run the higher it goes even with me slowing down). Walking as exercise my HR will be around 147-154. If I use the 180 method it has me at 137 bpm. I can’t walk and keep it at that rate. I am already gluten free and more fat dependent (my body doesn’t depend on carbs. I have ran two marathons taking in only about 80 calories during the 26.2). Am I just an anomaly that the 180 formula won’t work for? Or can I tweak it somehow to make it work for me?

    • Jessica:

      Generally, we tell people that they shouldn’t mess around with the 180-formula. However, in light of the fact that you only ingested 80 calories during a marathon, you may be the anomaly you mention. My best recommendation to you is to go get your RQ (respiratory quotient) tested. Look for whatever heart rate you find that your RQ is .87—that’s your MAF heart rate.

  • June says:

    Hi I am 58 with a resting heart rate of 57, however my heart rate increases rapidly when I do any form of exercise? I run at an average of 175BPM which compared to your 180 method is far too high. I am very active running 4 times per week, cycling once per week and weight training on another. My heart rates goes high whatever I do. What do you suggest I do? I have been active at this level for 3 years. My heart rate decreases quickly too. I have a bundle branch block Help

    • June:

      That’s a question best left to a cardiologist. What I can tell you is that in 99.9% of cases, an increase in heart rate beyond MAF amounts to increase in anaerobic activity. One thing that generally helps slow the heart rate and bring down blood pressure is breathing exercises. That may help you control the increases in heart rate to some extent.

  • Mike T. says:

    Hello! I’m so glad I found this program. The best thing ever. But I have a problem I’m hoping you can shed some light on. So I take thyroid hormone replacement and after monitoring my heart rate for the last 2 months while keeping my heart rate in the MAF zone, I’m beginning to think that no matter what I do, the thyroid meds will control my heart rate regardless of my increased aerobic efficiency. I started this program in quite good shape but see no evidence of a change in my heart rate. In light of this how would I know when I can start to train at a higher intensity after building my aerobic base? Thanks

    • Mike T:

      All bets are off with thyroid meds—it’s an issue best left to your doctor.

      The problem is this: hormones control your metabolic rate. Usually, these hormones fluctuate in relation to exercise: through your thyroid, your body ups your metabolism when you exercise, and reduces your metabolic rate when you stop. But when you are taking thyroid hormones, you create a hormonal steady-state, so that your metabolic rate (and yes, your heart rate) correspond not to the level of exercise—as they would in a body with a healthy thyroid gland—but to the level of thyroid medication you have in your body in real time.

      I’d suggest consulting a health professional who understands thyroid problems in athletes.

  • Bryan says:

    I’ve poured over the comments from this article and others and can’t seem to find the answers I’m looking for. I have found that there are a great many folks similar to me and that makes me feel much better about where I’m at physically. I’m one of those that have a HR that forces me to jog at an annoyingly slow pace and walk on the slightest of inclines. My “run all day pace” has my HR floating between 160 – 170.

    On to my question/dilemma;

    45 y/o male
    5’7″ @ 175lbs
    resting HR ~54
    MAF test (4 mile avg. on treadmill) 14:10
    Fairly muscular build

    I’ve been working out for years. That includes everything from weight lifting, to crossfit, to trail running, yoga, etc. etc.

    I “train”, if you will, for the sake of staying healthy over the long haul of life. However, I train hard for the sake of running OCR’s. My most recent was a 12.7 miler that I finished with a 14:21 pace (for perspective that was top 8% overall).

    It’s obvious from my MAF test that my aerobic base needs serious development.

    I’ve been using the MAF method for a couple months now for the endurance portion of my training plan. However, I can’t pull myself away from my crossfit style/strength workouts for a couple reasons; (1) I feel they’re necessary to compete in the OCR’s (2) I fear that running alone will deplete my muscle strength.

    Currently my training routine is something like this;
    M, W, F = HIIT or strength training ~15 – 30 min sessions
    T, T, S = MAF ~ 60 – 180 mins

    I’m sure you’d recommend that I do MAF base building only for 3-6 months. But I’m hoping you could find a reasonable recommendation that would include some time for strength training.

    Is it reasonable to expect decent aerobic gains if I do 80% MAF and 20% HIIT?

    Thanks a ton in advance, for your time and effort,

    • Bryan:

      What we usually recommend for healthy people is for 20% of total athletic activity (which includes races and anaerobic training) to be anaerobic, and 80% to be aerobic. To give you an idea of how far you can take this, the Dutch Olympic speed skating team—speed skating being an overwhelmingly anaerobic sport—trains aerobically 80-85% of the time.

      The times when you want to do exclusive aerobic activity are:

      1. During a period intended for aerobic base-building.
      2. If you are ill, injured, or overtrained
      3. If you are recovering from any of the three

      Of course, aerobic gains aren’t as fast if you are doing 80/20 than if you are doing 100% aerobic. You might make aerobic gains at half the speed.

      The most important reason to train aerobically is so that your aerobic base is strong enough to absorb your training and racing needs. Generally speaking, however, you can’t keep your aerobic base healthy unless you follow the 80/20 rule.

  • […] straightforward stuff: work out your aerobic threshold, never run over your aerobic threshold. To get your number: it’s 180 less your age. Adjust for injuries, for training history, for being c…. I get 141, which is a slight difference to where i was before… I had been using 145, but truth […]

  • Nicole says:

    I am 55 and been running 3-4 times a week on average for the past 2 years. I also did my first marathon this year and did a time that I was more than happy with (4:13). However during marathon training I developed Achilles tendinitis but ignored it so over the summer I was eventually forced to take 2 months off running. I started back training in mid September (so 2 months now) and was soon running 3-4 times a week. Then I decided to give MAF training a go. I started last week. I calculated my MAF HR to be 180-55 =125-5 (time off over the summer) = 120. However I am finding it excruciatingly hard to stay at under 120. I seem to be most comfortable (meaning I can actually trot and not walk) at around 120-125. Is it OK to set 125 as my MAF heart rate? Thanks for your advice.

    • Nicole:

      If you are coming back into training from an injury, it pays dividends to be conservative. If attempting to run insistently puts your heart rate over MAF, running is creating stresses that you may not want to subject that newly-recovered limb from. And make no mistake—a limb that is recently fully healed is nowhere as strong as a limb that’s been subjected to continuous training for a few months. My recommendation is to walk: take it slow, and you can expect to be jogging in a month or two.

      It’s not worth it to jog with a newly-healed achilles tendon and risk re-injury, particularly if you have the option of strengthening it for a month or two and then begin running with the confidence that the tissue is ready to withstand those stresses.

  • RM says:

    Hi. I came in contact with Maffetone’s “180-formula” more than one and a half year ago, after running my first marathon (which took me 4 hours). I decided to try it and for roughly 5 months I run exclusively at MAF HR. At the same time I also changed to minimalist running shoes. Also, I changed my breathing pattern to very slow nasal breathing (5 steps in, 4 steps out), while prior to this I could not breath nasally while running. I even reduced the intake of carbohydrates (especially refined sugars), and started running in a fasted state.

    The thing is, while I was able to improve 10 minutes in my marathon time a year later, I did not see benefits in my aerobic condition. Sure, I love running in minimalist shoes and my gait is much better now. Sure, I run more relaxed and I am now able to breath nasally during the day. But my MAF test results haven’t improved since! My best one is still the first one I took! (One thing I did notice is that my MAF Test is hugely influenced by temperature – I see a big correlation pattern in my times with the increase of the temperature.)

    So my question is… Why isn’t my MAF Test getting better? Could it be because I’m not putting enough volume? I run 55/60-minute runs twice a week, sometimes I am able to add one more of 25/30-minutes. So we are talking about 2h30′ a week at most. Is this too little to see some improvements? I really don’t have the available time to increase this volume right now.

    I really try to believe this method, and I have read lots of successful stories, but frankly I haven’t seen any palpable improvements in me.
    Any tips are welcome.

    • RM:

      For breathing, I’d recommend 2 steps in, 3 steps out.

      How stressful is your lifestyle? Any stress basically decreases aerobic function, which makes it more difficult to train the aerobic system. You should look at reducing allergies, improving sleep quality, trying to eliminate sugars and carbohydrates (even further than you mention), etc.

      About switching to minimalist shoes: although it is undeniably a good thing, it can also be a stressor, for the simple reason that switching to minimalism constitutes a change, and causes the body to break its previous rhythm and have to adapt to a new one. Of course, once adapted, you should see many improvements to your biomechanics and physiology.

      Let me make an important mention on the topic of temperature and MAF tests: while straying from optimal running temperature (either it being too hot or too cold) does reduce your speed, it doesn’t really reduce the amount that your aerobic system is working: in other words, your aerobic system isn’t working less if it’s too hot or too cold: it’s just using more of its energy to regulate your temperature. You’ll be burning fat calories at very similar rates, which means that if you train through cold or hot seasons, you’ll see “spontaneous” increases in speed once you return to more optimal temperatures. But this isn’t because your aerobic system suddenly “got stronger,” but rather because it didn’t have to worry about thermoregulation and instead was able to put all its energy into increasing your speed.

      Running in a fasted state may also be misleading you about your present athletic capability: at any given time, the aerobic system is using both fats and sugars. For example, at their MAF heart rate, someone may be burning 60% fats and 40% sugars (although 99% of fats and sugars are burned aerobically). But running in a fasted state means that you are only, or mostly burning fats, which means that you are providing your body with energy at a reduced rate—perhaps at 75% or 80% of the rate you could supply if you had both sugar and fat available.

      Again, this doesn’t mean that your aerobic system is weaker (or that you are weakening it). In fact, forcing it to rely on more fats means that when you do add sugars, your athletic performance increases phenomenally.

      Since you have a history with marathons, you may have to increase your training volume in some fashion. Do you presently do strength and power (anaerobic) training? If not, I’d recommend this:

      Add a bit of strength and power training (no more than 15% of your total volume) and use the MAF test as a diagnostic tool. The strength and power training should help decrease your time, but it will start to detract from your marathon performance if it creates too much stress for your body (again, because stress decreases aerobic function).

  • Anthony says:

    I’m a 37 yo male, and have been training at what I thought was MAF for the last three months. 180-37=143. I made some improvement, and my pace was mid 9:00s with very little heart rate drift. However, I’ve always ignored the instructions for taking another 10 beats off for medication. I was diagnosed with hypothyroidism while a teen, and I figured because its under control by taking synthroid that I don’t need to make the adjustment. I assume I am wrong. Should I take another 10 off? What are the consequences of not doing this? Does this mean that because I take meds I will never be a fast runner? I ask because I believe I read somewhere on here that someone’s half marathon pace is usually 10-15 bpm higher than their MAF. But if I subtract 10 from my MAF, would my HM pace be closer to 20-25 higher than my adjusted MAF?

    • Anthony:

      Thanks for your comment. Yes, you should take 10 beats off. This does mean that in the short term, you won’t be able to run as fast as if you included those 10 beats. However, taking 10 beats off means that you will likely develop your aerobic system in much greater measure, and much more surely, than with those 10 beats.

      The consequences of not taking those 10 beats per minute of are likely that you’ll do most of your training in a mildly anaerobic state, resulting in slightly more stress, slightly less recovery, and therefore slightly less development of the aerobic system. Over the long-term, this means that you’ll be a slower endurance athlete. Taking those 10 beats gives you a much better opportunity to increase your endurance performance.

      About your last question:

      You’re not subtracting 10 from MAF—you’re subtracting 10 from 180-Age to find your MAF. (In other words, there is no “adjusted” MAF). So, your half-marathon pace will be closer to 15-20 BPM above MAF (5-15 BPM is usually what I give for marathons). However, don’t just take this number and go with it: some people can perform at higher heart rates quite well. We just give 15-20 as an initial suggestion to test out and see if it works.

  • Gavin says:

    Hi Ivan,

    I’m 3 weeks into the ‘program’ and while its been frustrating to slow down, I believe there is a big payoff to be had with this approach. I’m 35 years old and have been training inconsistently so my MAF is 135. My question is simple – Should I be training for an average HR of or less 140 or to always have my HR under 140?

    I’ve been averaging a HR of ~140, but at times I bump up to 150+/- and then walk for a bit until my HR drops to 125-130 and then start running again. Is it ‘bad’ to be ever running a above my MAF of should I aim to always be at or below?


    • Gavin:

      A few bumps in your heart rate isn’t something to worry about, as long as you try to minimize them and attempt to stay under the MAF HR completely. For example, the situation you’re describing happens to me a few times every run. What you do want is to look at your real-time heart rate: to use an extreme example, an interval session where 20 minutes of sprints is done at 180 BPM and 20 minutes of recovery jogging is done at 120 BPM averages out at 150 BPM. So the average heart rate of a session may not be always representative of the primary effort (which in the case of intervals is overwhelmingly anaerobic).

      So, if you aim to stay 4-5 BPM below, for example, you’ll do just fine.

  • Darwin says:


    First, want to say that this is an amazing way to exercise. I’ve been doing this since August. Haven’t done the MAF test, however, at this point, I really don’t think I need to. Hang tight. 🙂 I have noticed HUGE, positive, changes in everything. I normally do Insanity, Asylum, T25 or Insanity Max 30 workouts as my main source of exercise – especially when traveling. I also mountain bike, ride horses (active riding with an elevated seat), do ranch work and a bunch of other things. I have had, for the past 15-years, chronic low-back pain. Since I’ve started working out, this way, my lower back pain has been improving by leaps and bounds to the point where, the other day, I had to lift a water logged manure spreader full… and I didn’t feel the normal “warning twinge” in my lower back. That’s the first time in 15-years… my footfalls/steps are getting more and more even, every single day. I feel more power and strength in my plyometric workouts. My overall biomechanical balance is improving my leaps and bounds and some stubborn body fat, that I’ve spent years trying to get rid of is, now, slowly melting away. Now, if I would just get my eating a little more disciplined some of that might change even faster, but I do enjoy a Peppermint Latte and a Cinnamon scone every once in a while. 🙂 This method rocks, in short. My mountain biking has improved by leaps and bounds… after just a month of working out, like this, I improved my mountain bike speed by 1.1MPH on my local trails which makes me pretty happy.

    OK… there’s a question in here, somewhere… I read through all 321 printed pages of comments on this thread and I can’t find anything related to what I’m about to ask. If it is there, my sincere apologies. I’ve always been a fan of the Polar heart rate monitors. I’ve had an FT40 for ages and it’s an old reliable thing that, finally, died on me. I just got myself an A300 with the H7.

    When Polar starts the workout phase it sits and watches heart rate variability, as I’m sure you know. At some point, the heart beats stop being variable, the system sort of “tenses up for what’s to come” and, at some threshold heart rate, the variability goes away. Polar calls this threshold the Fat/Fitness threshold. Below the calculated number your body is, supposedly, in Fat Burning mode and above it you’re in the “Fitness” mode.

    Here’s the question coming up through all the words… 🙂 If I’ve eaten well (low carbs, balanced fats, etc) for a few days and I’ve exercised/rested appropriatly, the FT40 and A300 calculate my Fat/Fitness threshold, most days, right at my MAF number (180 – age). On days when, prior, I’ve eaten poorly, over exerted myself, or I’m suffering from my seasonal allergy, etc, that Fat/Fitness threshold is some value lower. On days when I’ve really done poorly, it’s been really low. The question is, is there validity in using the daily-measured Polar Fat/Fitness threshold number as the MAF number? On days when I’ve done poorly, prior, it seems to be around 5-10BPM under my MAF number. There have been a few days when it’s calculated that value about 5BPM higher than my MAF number (Polar says it can range up to 80% of the Max HR on a REALLY good day, for a pro athlete with a highly developed aerobic system).

    I know that there are a few articles, on the site that discuss HR variability and its relationship to training intensity, and whatnot, but I’ve not seen where there has been a deeper dive into using HR variability to assist with determination of how hard to train for that day. There were just some general comments. I guess the reason I’m asking this, is that I’ve read all the stuff that Polar has to say about HR variability and how that plays into what Polar feels is the Fat/Fitness crossover. I get that and there seems to be a link/application, maybe, to this method as well. I know that you, and Phil, have discussed that heart rate, in general, is a solid representation of the absolute amount of energy put into producing a given effort (all systems involved). There is, also, the general discussion around the subtraction of 5/10 depending on drugs and physical condition… I’m just wondering if the Polar HR variability measurement might provide a bit more “support” (for those of us that have it) in terms of better maximizing our work/training/exercise, based on the current, measured, physical condition for that day and, if the calculated threshold is low enough, a clear indicator that rest is the only exercise that should be done, that day…

    OK… I need to quit now, as that got a bit long-winded. I, sincerely, appreciate the time/effort you put into reading, and responding to, these questions/comments. Thank you.

    • Darwin:

      That’s a very interesting question.

      Heart rate variability thresholds have to do a lot more with the neural response to exercise than with the metabolic response. It isn’t likely, for example that your aerobic threshold (MAF) would ever be 80% of your MAX HR—your aerobic threshold is a measure (among other things) of the amount of mitochondria you have in your body, which does not fluctuate with your heart rate.

      Let me put it this way: your MAX HR measures the maximum stress your body can handle at any given time, and your stress levels correspond directly your heart rate, unless you are in late-stage overtraining. But in order to maximize aerobic activity, you need to be below a certain threshold of stress (MAF). Going above this threshold will increase anaerobic activity.

      I’d say that until we have experimental data exploring the relationship of HRV to aerobic function, stick with the MAF HR.

      You could go test this theory at an exercise lab: see how the HRV threshold fluctuates relative to RQ (respiratory quotient). The MAF HR—aerobic threshold—is a respiratory quotient of .85-.87. If you find that an RQ of .87 always or nearly always coincides with HRV threshold, regardless of whether the HRV threshold is higher or lower than before, you’re very much on the right track.

      And by all means, if you do this experiment on yourself, please let us know the results. We’re always looking for correlates of the MAF HR—we’re trying to build a much more holistic view of the body, and your results could tell us a lot.

  • runnerD says:

    Hi Ivan,

    I submitted this as an inquiry via the contact page, but thought I’d also put in a comment here, since you seem to respond fairly quickly, and in case others were in a similar situation.

    I recently had a metabolic rate test done to measure my RQ during a treadmill test. My results don’t fit the MAF formula at all, and has left me wondering how I should proceed in optimizing my training. I hit RQ = 0.85 at a HR of 190bpm, while my calculated MAF HR is 146. At a HR of 146, the test results showed that I was burning about 80% fat. However, at a HR of 190bpm, I was only moving at 6 min/km. Slow!

    For the past 4 months or so, I’ve been training at my calculated MAF rate (146 bpm), assuming that I’m just a terrible fat burner because I’m moving hardly faster than a fast walk. But my test results show that my body pretty much only burns fat!

    I’m wondering now if this may explain why I’ve never been able to get faster over the years – I find it uncomfortable to run at a HR equivalent to RQ 0.85, so I can’t consistently train in that threshold zone needed to make improvements. Could this be true? Can it be that my aerobic system is dominant, but just produces no power? I.e. am i just hooped in terms of ever being able to run faster?

    Thanks for any insight or advice you can give.

    • RunnerD:

      Can you tell me more about your athletic and training history, as well as notable injuries and illnesses you’ve had?

      • RunnerD says:

        Hi Ivan,

        Thanks for the reply!

        Athletic history: I don’t have an athletic background, never played sports as a kid. Took up backcountry hiking and skiing in my early 20’s and that’s when I also took up regular ‘jogging’ to help with fitness on trips (10k casual road runs a couple times a week). First time I followed a training schedule was for my first half marathon in 2011. Then went back to casual running after that. Two summers later I discovered trail running and got hooked, doing my first ultramarathon in spring 2013. I’ve a done a few more of those since, and trying to aim for 100 milers.

        Injuries: I am currently coming back from long-term knee problems that started end of summer 2014. At its worst, I was unable to sit in a chair or walk without significant pain for several months, stairs were nearly impossible. Eventually got back on track with the help of a great doctor (and a short stint on neuropathic pain meds) by end of this summer and have been very slowly increasing mileage again since, now way more conscious and careful of overtraining than I ever was. I think running slow has been good for my ongoing recovery so far, as the knees are still improving every week. But now I’m looking to get faster and trying to figure out how..

        A friend recommended I look into the Maffetone method last summer, so I took up that torch with disciplined gusto in both training and diet. I haven’t been consistent with the training on account of the knee problems, but have been strict with the LCHF diet.

        • RunnerD:

          I’m seeing one big thing: The kind of muscle imbalance that creates pain when you flex and extend your knee (and when you leave it flexed for a while) has to do with the fact that when you put weight on that leg, the wrong muscles activate to carry that load, usually due to incorrect alignment at the hip. So, because the wrong muscles are loading that leg, muscles activate (and deactivate) in the wrong order to flex your knee. The reason that it’s extremely painful to climb stairs is that when you step with a flexed knee, and the wrong muscles are under load, the entire system freezes: it can’t extend, because that would mean relaxing muscles that weren’t working well in the first place. “Pain” is a symptom of this frozen mechanism trying to open and close.

          Because running is a cyclical switch from unloaded knee flexion (swing) to loaded knee extension (stance), “knee improvement” means that you are going from using the wrong muscles at the wrong times to the right muscles at the right times.

          This means that you are moving away from using one set of muscles which you have presumably used (and trained) for a while towards using another set of muscles which you have not used (and not trained) for a while. Making this switch means that you are using weaker muscles, which will necessarily bring down your speed, until they develop.

          I suggest that you take up single-leg deadlifts, first unweighed and then with very little weights (putting the weights on a platform where you can reach the kettlebell handle or dumbbell just below knee height). There’s a lot of good single-leg deadlift instructional videos on the internet. Look for videos that talk about how to maintain good neck, spine, and leg alignment. This exercise is instrumental in developing good motor control of the very muscles that may be contributing to your knee pain. The most important caveat here is to ALWAYS stop ANY exercise if it causes you pain.

          • RunnerD says:

            Hi Ivan, I wasn’t actually looking for advice about my knee – I’m trying to figure out why I’m such an outlier from the Maffetone method in terms of my RQ/HR test results, and how to optimize my training to improve speed, given my test results. You asked about previous injuries, so that’s why I described my knee issues, but there are a lot more details about it that I won’t get into!

            I suspect the answer is that the Maffetone method will simply not work for me and I will just need to figure out my own way to build speed and endurance, while avoiding injury.

          • RunnerD:

            My point is that your running biomechanics are inextricably tied to how you use energy, particularly in terms of how your body decides on percentages of fat and sugar to use for fuel.

            When you are starting to use muscles that you haven’t used before, the fat oxidative capabilities of those muscles (using oxygen to burn fats) is quite lower than the surrounding muscles, so your body has to rely more on (1) sugar, and (2) particularly anaerobic use of that sugar: in order to use muscles for endurance, your body has to create a lot of infrastructure, such as capillary networks, in order to get fat and oxygen to those muscles. (Not to mention that the muscles we’re talking about are generally speaking a lot weaker than the surrounding muscles, which means that they have to run at a higher intensity, relatively, to be able to keep up).

            So, your body is left no choice but to use primarily the fast-twitch muscle fibers within those muscles (which run on sugar and are more anaerobic), which means that it has to alter the hormonal makeup of the entire body (increase the stress response, increase the heart rate) in order to produce the power that will allow weaker muscles to work at the level of muscles that have been trained for a while. So the body as a whole will start working anaerobically to some degree. That’s a problem because anaerobic activity means stress, and we don’t want to stress weak muscles. We want to train them slowly, and once they’re strong enough, then we can start asking more of them.

            In order to continue functioning aerobically, you have to lower your speed dramatically (as you’ve experienced) so that your metabolic rate does not exceed the aerobic fat-burning capabilities of the muscles that you are just bringing into play.

            To use the metaphor of a sports team, your brain (the coach) has to tell the entire team to slow down to the level of a few new players (those untrained muscles) so that they have a chance to catch up. Or alternately, if the coach forces the new players to perform at the level of well-seasoned players, they’ll quickly become disproportionately tired. Some of those players may succeed, but others won’t.

            By taking it easy when you have muscle imbalances (running at an aerobic pace, regardless of how frustrating that pace must seem) we increase our chances that all of those players will ultimately come up to speed. My suggestion to you in terms of taking up single-leg deadlifts (and related exercises) is meant to help bring those new players up to the the level of the rest of the team, and in doing so, allow the team as a whole to more quickly rise to a higher level of performance.

            In essence, this is what the Maffetone (now MAF) Method is about: Developing a holistic vision of the human body (and of our own body, mind, and life in particular) in order to find the quickest way towards lasting, sustainable athletic achievement. Aerobic training is our most common prescription since usually, the ways towards better performance occurs by first removing negatives and then increasing positives. As the negatives increase in number and magnitude, chronic anaerobic activity increases, and aerobic activity decreases. And as the negatives decrease, aerobic activity increases.

            Removing the big negative affecting your athletic output—the muscle imbalance that results in your knee pain—is the first step towards greater aerobic function. Increasing positives—bringing the weak muscles up to speed without overstressing them—is the second step. There may be more steps to take, but I guarantee that you’ll have to take at least these steps, in this order, in order to produce lasting, sustainable athletic achievement.

          • RunnerD says:

            I should add that I definitely agree with your comment that I am now using different muscles, which may be bringing down my speed until they develop more – that’s a good point. I have been focusing on improving my running form and biomechanics (having to run slowly makes this easier to do!). I just don’t know what HR range to stick to now.

          • RunnerD:

            I gave a more protracted answer in my previous comment, but I didn’t include an answer about heart rate. I’d suggest that you do most of your running at the MAF heart rate, even though you’ll find it to be very slow.

            1 or 2 days a week, I’d suggest that you do some strength and stability training (particularly in the form of single-leg deadlifts and similar one-legged-stance exercises) which will help (1) pattern correctly and (2) develop the muscles that were creating the knee imbalance. And don’t exert yourself—the point isn’t to “train” or “tire” those muscles, but rather to help them work together with the rest of the team (musculature).

            Those days, I recommend that you also do some slightly quicker running for 15-20 minutes, the point of which is to take the new motor information from the strength and stability training and incorporating it into the running gait. Whatever works for you—15 BPM, 20 BPM above MAF (or even higher). The important part is that the length and intensity of the running session doesn’t cause you pain or discomfort, particularly around the knee area, and that you don’t finish (or wake up the next day) cramped, sore, or exhausted.

            If you can go from the strength/stability training to the short running session without having to cool down and warm up again, the crossover of information from the strength/stability session to the running session will be excellent. And if you can do overground running instead of treadmill running, this effect will be even better.

  • Jim Stanton says:

    Hi Ivan,
    A quick update and a couple of questions.
    I’m beta testing the MAF app….so far its working great, I’ve ordered an bluetooth compatible HR monitor so I have not done my official aerobic function test yet. I’ve completed the surveys and my “official” aerobic heart rate is 99bpm. I’m 76, been running for 40 years and I was having trouble keeping my HR below 104 (180-76) but at 99 i have to walk but it requires more than just a brisk walk. In order to stay in the 95-99 range I have taken to carrying ankle weights in my hands and by varying the amplitude of my arm swing I can fine tune my HR.
    It’s kind of ironic, before I couldn’t run slow enough now I can’t walk fast enough. I’m walking at about a 16 min/mi pace and it takes some focus to maintain this pace. Question, is approaching the target HR from below in this manner a reasonable approach? Do you think as I spend more time in this mode that I will be able to break into a slow run at this HR?
    Thanks in advance for any comments or suggestions


    • Jim:

      You will, but there’s a way to speed it up: I’d recommend that you take up jumping rope, even if you only do short 5-minute sessions.

      The approach you’re taking is pretty reasonable, for now. What I suggest is that you keep your shoulders loose and mobile—don’t clench them up in order to drive the weights up and down. Also, now is a good time to practice the running arm swing: go from hip to collarbone. I tell people that if you do a thumbs’ up, the downswing should end with your thumb touching the top of your hip and the upswing should end with your thumb touching your collarbone.

      (It’s slightly exaggerated, but training it like that will help once you get into running).

      What jumping rope does is mimic part of running (the shock-absorption and energy return of landing), while leaving out the forward motion. So, by jumping rope you are creating only a small part of the stresses of running, while training the thing you need to be able to do in order to run well but can’t train exclusively by walking.

      (The reason, in fact, that people sometimes can’t run slow enough but can’t walk fast enough is because the shock absorption+energy return component of running has a big metabolic cost.) So, if you run and walk at the same (very slow) speed, you’ll burn far more energy (and have a far higher heart rate) running than walking. Allow me to state the obvious: what makes running useful, despite the fact that it is more costly at any speed, is that you can produce speeds much faster than you ever could while walking.

  • Matthew says:

    I have a question on intervals and their effectiveness in developing aerobic capacity using the 180 Formula. (I am 24, so my MAF is 156 bpm) I love doing intervals (tempo runs, jump rope, full body circuits, etc.) and don’t really like going for steady-state runs. When I am performing my intervals, should my “working” HR be the 156 I calculated (and not go over this HR), and then during the resting periods allow for a drop in bpm momentarily? And do you suggest a specific HR (like 120 bpm, for example) for for my resting intervals before ramping back up to 156?

    Or do you not suggest intervals at all? Are you suggesting that just doing a steady-state running/biking session around 156 bpm is better for developing aerobic capacity?

    Thank you so much for taking the time to answer all of these questions! I have read through the majority of them and it has really helped me understand so much!

    • Matthew:

      There’s a place for intervals, and there’s a place for steady-state runs. What intervals do is to create bouts of intensity from which you then need to recover from.

      But when intervals are done under an aerobic heart rate, there’s no need to recover from them because both the peak and the valley of the interval are using the energy system that you would use for recovery in a typical interval session. If, in an only-MAF interval session, your HR is going from ~30 BPM below MAF to ~5 BPM below MAF and back, you may be exercising 50% of the time close to MAF. So, you’re much better doing a steady-state run at MAF if your goal is to maximize aerobic development.

      That said, anaerobic training has a place. Typically, we recommend that athletes do 20% of their training anaerobically, unless they are ultradistance athletes who will be performing at or under MAF almost exclusively. But if you are a marathoner (or run shorter distances) and you train 10 hours a week, we are still talking about 2 hour-long interval sessions a week.

      • Henrik says:

        Hi Ivan
        Why is it that 20% of 10 hours training only is 2 half-hour intervals =1 hour? Which to me only is 10%.

        In the 10 hours training a week do you include or exclude the warmup/cool down?
        And how hard do you do the intervals if you train for a marathon? Is it at MAF plus something or just very hard?

        Thanks for your comments. I enjoy reading them all.

  • Jim Stanton says:

    Hi Ivan,
    I see your point about jumping rope….running in place is easier and more convenient for me and I can get my HR to the proper level and keep it there. It’s just like running with the exception of forward motion …I can’t believe I just said that.
    Is that as good as jumping rope?
    I received my HR monitor and tried to conduct my first aerobic function test. All went well until the about the middle of the test a large NaN appeared on the screen and the app froze. Will your developer request periodic feedback?


    • Jim:

      What I like about jumping rope for running is the same reason that boxers like it for boxing: the coordination challenge that it presents is very high. Furthermore, for running well you need to be coordinated between your arms and your legs. Even though jumping rope doesn’t require the same kind of coordination, some coordination is better for running than an exercise with no coordination demand, such as running in place.

      So I think that jumping rope is far superior to running in place as a drill.

      And I’ll get that feedback to my developer.

  • Manuel says:

    Hi Ivan:

    I can’t find a reason why it’s so hard for me to reach my maximum aerobic heart rate, although the associated pace is very slow. It seems to be the opposite to the most common situation. Any suggestion?
    I’m 47, running since 18 and it’s sometimes very hard to reach 128 bpm (being conservative I subtract 5 to my MAF heart rate). Anyway, the method makes a lot of sense to me and I am very happy following it, since I feel great, I don’t race and I don’t mind about the speed. I am just curious about what could be happening in my body.


    (I’m sorry for my english wich is not very good)

  • Kevin says:

    Is it normal to regress or is it possible the one-size-fits all approach doesn’t actually fit all?

    I started running last summer. By November was running between 20-25 miles per week. Started the MAF on December 7th. Even though my running before had been at what I considered an easy pace in which I could carry on a conversation (10:45-11:00min per mile), my initial MAF test was a extremely slow 14:14 average over 4 miles.

    I’ve plugged away for two weeks. Running about 4.5 hours the first week and 4.5 last week (I run 30-60 minutes at a time). However, after a few runs I was frustrated with “running” that I haven’t not been looking forward to going for a run anymore. It’s so slow and non-fluid as I can’t run slow enough or walk fast enough. So it becomes a horrible attempt to run slow until my HR goes above my MAF and then walk as fast as I can so it doesn’t drop too far and then back to running. But I went from putting in 6-10 mile continuous runs to now only being able to run continuously for 200-300 meters and then having to walk. I can’t find a rhythm that allows me to run for an extended period (even if it’s at a slow pace).

    Anyway, I’m about to give up but decided to do another MAF test today (2 weeks + 1 day after my initial test). I figured seeing an improvement of even a few seconds would help me keep going. The weather conditions were almost identical (about 4 deg cooler today and about .5 mph less breeze).

    Needless to say, my overall pace was slower and 3 out of the 4 miles were slower. First MAF test –13:42/14:23/14:32/14:30. Today’s MAF test — 14:07/14:10/14:42/14:48. Also my avg HR was 1 bpm higher on today’s run (not much but enough to say I “pushed” as hard today as I did the first day and a little bit harder)

    I’m 42 and am running at 133 HR (180-42-5) for being a new runner and dealing with plantar fasciitis (which has never been more than a nuisance so I can run through it but has slowly been getting better). I also am taking Omeprazole (Prilosec) for GERD but I’m not taking off another 10bpm from the already low 133. I would reach that HR watching Netflix… and the only effect it has on my running is when I don’t take it!

    I’ve been eating better since running. Not full MAF approved but better than before. I’ve lost 15 pounds since August. Don’t consider myself easily stressed plus I have a fun job that really has minimal stress. Life is good. Family is good. Sleep is good.

    So why does running at MAF suck so much? I think the worst thing to come out of it is that I’m losing the joy of running. I was having a blast and even coming close to getting that elusive runner’s high but in the last few weeks, I dislike the days I’m scheduled to run. I did them anyway, thinking I was going to see improvement and that it would be worth it. But after today….not so sure it’s worth it.

    Either there needs to be an adjust to the formula for it to work for me or I probably need to call it quits.

    This is part rant and part looking for answers. I should have shown improvement, but I didn’t. I just want to be able to go on a run again instead of this disjointed, arrhythmic jog/walk thing I’m having to do that is getting slower and slower.

    • Kevin:

      Thanks for commenting.

      The MAF approach is “one size fits all” in a very specific sense: the aerobic system (which burns fats) is responsible for keeping all of our bodies healthy. So it fits all of us—and it is particularly important for those who can a very hard time staying at the MAF heart rate, either because it “sucks” or because the speed is so slow.

      When it sucks to run MAF, the aerobic system is often underdeveloped below a critical threshold. Under this threshold, chronic illnesses and injuries are much more likely.

      Fats are a slow-burning fuel that the body burns in the long-term. As the body becomes a more and more competent fat-burner, its levels of energy become very stable—much more stable than someone whose body is only capable of burning sugar.

      Since the body has more energy overall when it is a powerful fat-burner, it becomes increasingly capable of investing in the processes and infrastructure that clear up chronic issues.

      Don’t get me wrong—it’s quite possible to become “fit” while also being unhealthy. But it’s absolutely impossible to perpetuate that fitness without being healthy. So, to use your terms, it is quite “worth it” to train MAF.

      This brings us to a new question: why does the body sometimes regress?

      For starters, two weeks is not enough time to show improvement. Think of it this way: the aerobic system, which burns fuel slowly and over the long-term, develops slowly and over the long-term.

      What you understand as a “regression” is most likely your body’s natural hormonal oscillations, which have nothing to do with “fitness.” The reason we recommend MAF tests once a month is to be able to account for these natural oscillations.

      You can’t hurry this process—which is why you can’t hurry the process of developing overall fitness. Attempting to do so is a major contributor to the present injury rates we see across sports.

      Most people, for example, start seeing the first improvements—5-10 seconds per mile, within 1 or 2 months. But given the right conditions, the aerobic system can continue to develop for a long time. For example, over the course of 2 years, Mark Allen went from just under 10 minute miles at his MAF heart rate to just under 6 minute miles. It’s perfectly reasonable for a non-elite to drop 1 or 2 minutes per mile at the MAF heart rate within one year.

      (To put this in perspective, a 1 minute per mile drop at the MAF heart rate equals a 26 minute improvement in the marathon).

      My advice to you is this: you have to stick with this for at least three months, in order to really begin to see “substantial” benefits. Let me give you some guidelines on what to do during that period of time:

      There is a difference between “aerobic competency” and “aerobic function.” For example, Galen Rupp, who holds just about every American distance running record, has asthma. While he has a massive aerobic competency (because of his fitness as a distance runner) his asthma means that he is often at risk of losing aerobic function.

      In other words, any stressor—asthma, allergy symptoms, visiting family, bad nutrition, poor sleep—can put the body into “panic mode,” reducing aerobic function. (For example, people’s MAF speed may decrease 2 minutes per mile when they have a cold). They haven’t lost fitness, but the stressor means that their aerobic system is impaired.

      When the aerobic system is impaired, it is less “trainable.” So, a big thing about MAF—and this is where MAF diverges even further from the “one size fits all” model—is that it is just as important to remove stressors in order to promote aerobic function, as it is to train at the MAF heart rate and develop aerobic competency.

      Does this help? I hope I’ve answered your question. Please shoot back with any more questions or clarifying comments.

  • Brian says:

    I’ll try again the last post seems to have been removed?

    A couple of queries – I am 57, 58 in 2 months so my MAF is 128 123 +5 I’m a regular trainer at least 10 – 12 sessions a week and have done so for at least 5 years.

    While reading a article by Mark Allen he suggested that while following this system you should add a further 5 beats if you are over 55 years old do you agree? I ask because my run rate is very slow and I just want to make sure I’m training at the correct heart rate.

    I intend to train at the MAF rate until April then add 20% anaerobic training in preparation for my main event an Ironman in October is this the right way to go? After the race I will switch back to the MAF rate and train for a further 3/4 months before adding any further anaerobic training.

    Am I on the right track? If not a couple of pointers would be appreciated.

    • Brian:

      I apologize. I was away from the comment sections for the holidays. Adding 5 beats is OK, as long as you’re not injured, overtrained, or generally healthy. You can think of the 5 BPM addition for people over 55 as discretionary, not mandatory.

      An Ironman is an overwhelmingly aerobic sport. By training anaerobically, you won’t really be developing any biological systems that you’ll be using during the race. For an Ironman, I wouldn’t worry about training my anaerobic metabolism in the typical “do intervals” kind of way.

      Stick with aerobic training, and for your 20% do sports-specific training such as drills to increase your running cadence, stability, strength, etc. Also, I’d recommend course-specific training: for example, training hills of the typical length and duration of the hills you’ll find on the route.

  • Fred says:

    Hello Ivan,
    Ref my initial contact dated 26th July 2015.
    My MAF is 180-66-10+5 (for running a few years without injury) = 109 BPM.
    My Garmin 220 Zone 1 is programmed for 99 – 109 for every day ‘easy’ run pace.
    I still have problems keeping within my MAF HR range because I’ve always been training for something, albeit slowly.
    To be honest, since August 2nd, I have logged 108 runs with an average heart rate of 122 BPM.
    (Nike Plus info)
    When I first made contact, I was following my Berlin Marathon training program.
    I ran a 10:50 min/mile (4:43:37) with an average heart rate of 132 on the day.
    The first half never topped 132 BPM.
    Today, (after an ‘easy’ 4 miler), I decided to carry out a walking test to check on my heart rate and found that after walking briskly for 1.5 miles at approximately 116 paces to the minute (military pace) my heart rate feedback read, 93 to 107 BPM at 14:37 min/miles. This leaves me very little to break into a jog and still develop my aerobic base. Just a point to note Ivan, I have logged several 10 milers since August, when my heart rate recorded an average of 108 BPM with 118/119 maximum, but my pace was only 11:40 and 11:14 min/miles.
    Would you be good enough to advise me further? Regards, Fred

    • Fred:

      The heart rate spikes you mention aren’t enough to really reduce the speed at which your aerobic base develops. Your racing heart rate for a marathon should be 5-10 BPM above MAF.

      One thing I’d recommend is that you take up jumping rope. It helps train the ability to absorb shock, the same one you do running. So, jumping rope a few minutes a day helps bridge the gap between walking briskly and starting to jog.

  • Melissa says:

    Hi Ivan

    Thanks for your lengthy and detailed comments throughout this site. I’ve learnt a lot reading them!

    I am currently in my base building phase, having used MAF for around three months. I have a question about the Pear App. I’ve recently started using Phil’s 60 minute workout in Pear which is his classic aerobic workout. My question relates to the heart rate zones on the Pear App. My MAF HR is 180-43-5=132. On Pear, there is a calibration workout, which has calculated my zone 2 as 118-136 BPM. As you can see, my MAF is right in the middle of the Pear zone 2, however, it allows a few more BPM on either end. Would you advise against allowing myself to reach the top end of the Pear zone 2, given it is a little higher than my MAF? My perceived effort isn’t markedly different around 136 BPM although I am running faster at that heart rate. (NB I subtracted 5 BPM from my MAF because of lack of training in the last 2 years).

    Best wishes

    • Melissa:

      It’s best to not listen to perceived effort. If you want to develop the aerobic system safely and maximally, you should stick to MAF—even a few beats per minute above MAF is enough to activate a slight anaerobic response.

  • Susan says:

    Hi Ivan
    Thanks for your ongoing detailed and informative replies here. I hope I haven’t missed the information that I’m looking for in earlier replies. I feel a lot like Kevin in my frustration (post on Dec 23 2015) . At a MAF of 135 (45 years of age with good health, consistent training and no recent injuries), I really struggle to be able to run at all while maintaining the heart rate. It’s this awkward walky-joggy thing that feels terrible. I can normally maintain about 6min/km pace for 5km (not sure how that converts to miles, sorry – I’m in Australia), but clearly this must be anaerobic as my heart rate is up around 170bpm towards the end. I’m willing to accept that if I persist, this will take time and I will only see results in terms of months, rather than weeks. As someone who has historically got injured/over-trained reasonably easily, I’m keen to tap into the benefits that this approach seems to deliver. I’m not aiming for any super long distances, just be able to train more often, recover better/faster and maybe get up to 10km distance this year. My difficulty is that I play netball twice a week, which gives me no opportunity to control my heart rate and is, by nature, a sport that relies on anaerobic activity. Lots of start-stop, sprints and changing direction quickly. What I’m wondering is whether it’s even worth trying to build my aerobic competence in my running sessions if I’m undertaking anaerobic activity for two sessions per week. I’m only running twice a week at the moment to allow my body to recover in between sessions so I don’t get injured. What are your thoughts?

    • Susan:

      Running MAF does sometimes feel terrible. However, when our MAF speed is very slow, it shows that our aerobic system is very underdeveloped. Since we need a robust aerobic system to tolerate the stresses of life, training, work, competition, etc., we are essentially faced with a choice: we can either decide to feel like we’re training in the meantime—running fast to blow our hair back—or actually taking the steps that are necessary to become a healthier person and a better athlete. And when we have a history of overtraining (or of not training at all) one of those steps is invariably the development of a more potent aerobic base.

      Without it, we will find that our athletic ability collapses again and again due to injuries or illnesses that “came out of nowhere.” But they came from somewhere: they came from an aerobic base that was too weak to help the body effectively recover from the present stresses that it was subjected to.

      On building aerobic competence, let me put it to you this way: if all you do is eat donuts, it’s better to eat one salad than to eat none. You may be making a very small dent in the negative aspects of your lifestyle, but it is a dent nonetheless. That’s not to say that your situation is this bad: running aerobically two days a week is quite a bit of aerobic work. However, doing anaerobic work will eat away at your aerobic base.

      If the degree to which you are doing anaerobic work is less than the degree at which you are developing your aerobic base, you’ll see your aerobic progress slow, but not stop entirely. This isn’t necessarily a problem. To use an example, an olympic weightlifter has no need for an ultrarunner’s aerobic base. All they need is an aerobic base that will keep them healthy relative to the stresses of their preferred sport.

      And this is where you make your choice: what do you prefer? Do you want to be a distance runner, or do you want to be some other kind of athlete? If your aerobic base is progressing slowly, and you’re (say) a tennis player, then whatever stresses you’re incurring are acceptable, relative to your aerobic training. If your aerobic speed is deteriorating, you need to change the aerobic/anaerobic ratio you’re working with.

      Does this make sense?

      • Susan says:

        Hi Ivan – thanks so much for your prompt and detailed response. I did see it when you posted it, but I haven’t had a chance to reply before now.

        Yes – it does make complete sense. I love the salad and donut analogy! I’m really pleased that it should still be possible to build a sufficient aerobic base (albeit super slowly) while undertaking a couple of anerobic activities a week. I’ve already changed my exercise routine to ensure I am doing more aerobic work than anerobic to make sure I am (hopefully) continuing to build. Time will tell, I guess!

  • Jon Arrowsmith says:

    So I really have two questions. I am 37 and am subtracting 5 beats just to play it safe which gives me a MAF of 138. I usually average around 135 or 136 over the course of my entire run and slow whenever my heart rate hits MAF or goes over. I started MAF training in December which was relatively warm here. Temperatures were in the mid 40’s F. Now they have dropped to 30F and below. My pace has taken a significant drop of about 30-45 seconds per mile in the colder weather. Is this to be expected? Also I plan on running my first 50 mile race in April. I plan to train below MAF the whole time. At what heart rate should I consider running this distance? I noticed that you have recommendations for a half and a full marathon in previous comments.

    • Jon:

      Yes, it is. For example, when I went to San Diego for the New Year I was running 7:35 minutes/mile at MAF in balmy weather. Here in Portland, I’m back to running 9:30 minutes/mile. It’s the cold stress—crazy stuff.

      A 50-k should be run 5-10 BPM below MAF to MAF—it really depends on the person.

  • Alex says:

    Added onto my other comment, if you go over your suggested heart rate for a couple seconds is it a big deal? I just completed my first 4 mile MAF with an average BPM of 151 (aiming for 153) .. Also it’s 4 miles because apparently 8k on my watch only equals 4.77 miles hah.
    Mile 1: 11:11
    Mile 2: 12:11
    Mile 3: 12:38
    Mile 4: 12:05

    How come it’s all over the place? And whoa it’s realllllly hard to run that slow

    • Yeah, that’s fine. It’s all over the place because the heart rate responds in real time to any stressors (or any relaxing stimuli). If you get surprised by a car horn, or if you suddenly run out into an open meadow full of wildflowers (or whatever) your heart rate will almost immediately rise and drop some 10 BPM, respectively. Ditto with tiny uphills or downhills.

  • Alex says:

    Ok after reading all of the comments I get most of it, I just need a little clarification. Race pace should be 10-15 BPM throughout entire race (marathon) correct? That would put me at a max 165 for racing? Run 5 days a week for 75-90 minutes including 30 minutes for cool down and warm up? So more like 60 minutes of actual running, does this change when your training for a marathon? (Seems like low mileage in comparison to other sources). Lastly can I run like this all year round? As of right now I have no races in mind but I would like to start building my aerobic system… Does anything need to change when I have a marathon picked out and time starts to encroach on it?

    • Alex:

      We don’t give out mileages or times for people to train to: there’s no way of knowing if our reader is a completely sedentary person or an elite marathoner. The most important thing you can do is train as much as possible without increasing your stress levels.

      Basically, stressors of any kind (too much intense exercise, stressful lifestyle, bad nutrition, noise pollution, bad sleep, chemical pollution) drive down aerobic function. So, as I mentioned, you want to train enough, but you want to stay well below the threshold where training volume becomes stressful.

      All this said, you’d be surprised how little mileage you need to run a very fast marathon, if you do things the right way. One of the reasons runners find themselves increasing their mileage dramatically is because a lot of runners essentially exist in stage 1 overtraining—and so they need 80-85 miles to garner the same training response that a healthy (not stressed, rested, without muscular imbalances) body could get out of 50-65. And I personally believe that a lot of training programs almost unconsciously or reflexively cater to this ubiquitous “stage 1 OTS” runner because usually, that’s exactly who your client’s going to be.

      Towards a marathon, the best thing you can do is to do some course-specific strength and power training (hills, for example). A lot of marathoners do very well with 10%-15 of their training volume being anaerobic (tempo runs, intervals, etc).

      • Alex says:

        Thanks for the reply! Im currently gunning for a sub 3 marathon in oct, so a full 10 months of training. When i plateau on my MAF test is when i want to start incorporating speed work correct? and 10-15% would be maybe a day? so 6 days total? (i know you cant give specifics but following my body and knowing im healthy 6 days total? or keep it at 5 and remove one of my aerobic days?)

        I have one other question aswell, Im big into rock climbing and tonight i took my HRM with me to see what kind of zones i would be in, sure enough it spikes and falls alot putting me in and out of my anaerobic threshold. As much as i love this sport (it really is a big chunk of me) i would be willing to sacrifice it for a year to help with my running, basically how much does doing something like that hinder my aerobic building? For context i usually boulder 3 times a week for 2- 3 hours.

        Is it ok while running aerobically to go over for a couple of seconds (accidentally) and then just slow down and work it back to aerobic?

        • Alex:

          Yes, 1 day works just fine. What I also like to do is do “endurance” and “power” two-week cycles: for 2 weeks I train 95-100% under the MAF HR, and for the next 2 weeks I train 70-75% under the MAF HR. I’ve found that this helps me create a stronger training response.

          Rock climbing is an overwhelmingly aerobic sport: while there are lots of spikes in heart rate, these spikes have a relatively short duration and all in all constitute a very small percentage of total training time. To put this in perspective, the stability and shock-absorption requirements of running are basically all anaerobic (stability a faculty of Type IIX “super-fast-twitch” fibers).

          For example, this means that if you do lighter or less-intensity rock-climbing than you’re used to—if you don’t “actively push your skills” while you’re intending to build your aerobic base—the disadvantages of bouldering would be negligible, particularly compared to the benefits that varying your training has on the repetitive stress component of running.

          It’s OK to go over a couple of seconds—it happens to everyone. The trick is to work on the habit of learning how to keep the heart rate at the level you want.

          • Alex says:

            Awesome thanks for the replies Ivan! one last question if i may… In Dr. Maffetones 180 formula write up he uses this as an example

            MAF 5K 5K
            Min/Mile Race Pace Time
            10:00 7:30 23:18
            9:00 7:00 21:45
            8:30 6:45 20:58
            8:00 6:30 20:12
            7:30 6:00 18:38
            7:00 5:30 17:05
            6:30 5:15 16:19
            6:00 5:00 15:32
            5:45 4:45 14:45
            5:30 4:30 13:59
            5:15 4:20 13:28
            5:00 4:15 13:12

            How is he getting these races paces? is it a certain HR above your aerobic HR? At what HR are you supposed to run races?

          • I’m not sure how he got those numbers. But typically, for example, you run a marathon 5-10 BPM above the MAF HR, a half-marathon 10-15 BPM above, a 10K 20-25, etc. However, this really depends between people (because some can push very hard during races) and so the best thing to do is to test out whether a particular racing heart rate works for you.

  • Brian McD says:

    I started using a HR monitor today for the first time. Am I correct in thinking that aerobic fitness and anaerobic fitness are two different things? I am able to run at a decent pace, without feeling bad, at what the 180 formula would say is an anaerobic HR for me, and yet when I use my 180 formula HR, I find that I can barely run at a light jog on flat ground for more than a couple of mins without having to walk to keep the HR down. I find this quite disturbing, as I tend to run around my local mountains, and have no problem running 5 miles which incorporates steep climbs and descents. It seems so crazy that I wouldn’t have the aerobic fitness for a very light jog on the flat, which feels pretty effortless, but my HR continues to climb past the max HR.

    • Brian:

      You’re absolutely right. That said, I’m compelled to point out (something you may already know): aerobic fitness and anaerobic fitness aren’t something we can choose from a menu given our exercise preferences. The reason that pursuing fitness is commonly referred to as “developing the aerobic base” is because aerobic fitness essentially provides the health and recovery foundation on which anaerobic fitness must be built. Doing otherwise puts you at risk of ill health and overtraining.

  • Paulo Alexandre says:

    Hi After a test, I found out my running max HR is 191. Do I still use the 180HR as reference to get my MAF HR or do I use my max HR which is 191 as reference do get my MAF HR. For exemple my MAF HR would be 191- my age + 5(as I am an experienced athlete) or 180 – my age + 5? Thanks

    • Paulo:

      It would be 180-Age+5

      • Steve Houghton says:

        I am reading the information on MAF testing with great interest and understand the principle – but struggle with this concept of totally ignoring individual’s max heart rate and using 180. I cannot understand the science of that and it would surely seem more sensible to tailor based on Max Heart Rate as opposed to a one-size-fits-all approach. I simply cannot understand how this system can be considered appropriate for two runners of the same age and athletic history but with vastly different max heart rates. For example my running buddy and I are the same age (47), run similar events up to marathon distance and both have no medication or injury history to worry about. His max heart rate is 155 and mine is 203. But this system would suggest that we would be aiming for exactly the same heart rate training range!

        As I say I struggle with the concept. I’m not saying you’re wrong – but I don’t get why 180 is right for all.

        • Steve:

          The reason we do not tailor to the MAX HR is because fat-burning is a feature of the metabolism (whether your body is hormonally situated to burn fats) while MAX HR is a feature of the cardiovascular system (how hard your heart can pump). In other words, how hard your heart can pump is quite disassociated with whether you’re using fats or sugars. Don’t get me wrong—how hard your heart can pump has a very powerful association with how much sugars you are capable of burning, but not so much with when fat-burning starts to fall, and sugar-burning starts to rise dramatically.

          What is associated with the kind of fuel you’re burning is at what heart rate, relative to your age, fitness level, health quality, etc. your body maximizes the hormonal make-up necessary to burn fats at a very high rate. Indeed, because the 180-Formula accounts for these factors, I would hardly describe it as “one size fits all.”

  • Alex says:

    I have one more question, I ran my first full week last week. Started off at an average pace of 7:48/km and by Friday was down to 6:53/km average pace (all runs full hours). Now i took the weekend off and went for my run today and i was back up to a 7:34/km pace… it was extremely frustrating. Will it fluctuate like this often? how did i lose so much over the required 2 days off? (ill add aswell that even after my 5 days of running because the pace is so slow i dont really feel tired on the weekend, but i took the two days off because it seems like thats the consensus of what to do?)

    on todays run my avg pace was 6:21/km ….? is it normal to be so up and down?

    • Alex:

      You didn’t lose anything. Or more accurately, you can’t know. Fat-burning is primarily controlled by the body’s hormones that create the circadian rhythm (after a fashion), which means that fat-burning fluctuates with your body’s long-term hormonal oscillations. All the physiological systems that you’ve been exercising for those 5 days haven’t actually been growing all that much during that period: all the capillaries, mitochondria, red blood cells, etc. will do the majority of their development during the days of rest. And for that, 2 consecutive days is far better than 1.

      Other good possibilities is that you are sick (or beginning to get sick), or had a particularly stressful day, or haven’t been eating or digesting well. Any and all stressors can and do negatively impact fat-burning.

      It’s important to talk about why we get tired: the reason we get tired is, simply, because we run out of fuel (usually sugar). In other words, “getting tired” is only the measure of how much fuel you used; it’s in fact NOT the measure of how much your body is going to adapt from that workout. So, the reason that you’re not getting tired, is because you’re not running out of fuel. If you’re not running out of fuel, it’s because you’re using a much more abundant fuel source (fats) instead of a less abundant source (sugar). So, by not getting tired, you essentially have your proof that you’re training the bodily systems you intend to be training.

      The question remains as to whether you could be training them any more than you are now. The best way to know is to push the envelope: slowly increase the time you’re running per day (10 minutes every week, say) until you find a time that makes you tired. Then subtract 10 minutes from that time and you’ve found how much you should be training.

      But regardless of whether you’re getting tired or not, you have been using your fat-burning metabolism very very much (as evidenced by the time spent training), so it is not just important to take those two days of rest, but in fact critical to your development, since as I mentioned above, it is during rest and not training where growth actually happens.

      Oscillations are normal—you’ll find that they stabilize as time goes on.

  • RVS Reddy says:

    I am for the first time came across the material and it is enlightening.

    Little brief about myself. I am now 55 and an Indian Air Force veteran. I have been running since I was 17 in the collage and by gods grace, still doing as a hobby till few years ago when the ‘Participation in Marathon’ bug bit me. I have been participating in 10K/HM with 1 Hr and 2.5 Hr times but never thru a structured training either in group or alone.

    I am truly inspired to now work on 180 formula and when ready wish to participate in FM.

    Truly appreciate your advise on how do I proceed. A 55 year old, 82Kgs, with no ailments till now.

  • Darren says:

    I’m 45 so my MAF is 135 + 5 = 140 due to consistent training for well over two years with consistent improvements and no injury’s. I think I’m understanding the methodology pretty well for training and I’m going to give it a go. I’m curious though about race day. I read one post that said a marathon pace would be about 10-15 beats per minute over MAF. I’m gearing up for tri season and will be doing some olympic distance races and finishing the year with my first half iron. What kind of HR should I be shooting for in an olympic distance and in a half iron distance?