The MAF Method: What it is and where to start.

Primum Non Nocere is Latin for “First do no harm.” All health professionals learn this edict early in their educational process, as it is a driving principle of healthcare worldwide.

I have embraced this imperative ethical principle throughout my career, and my foremost piece of advice to people everywhere is that it’s a motto everyone should adopt. Both health and fitness are requirements for optimal human performance.

Unfortunately, rates of poor health and impaired fitness continue to rise worldwide. Most remedies for various ailments—whether they be food, drugs and dietary supplements, fitness programs or other therapies—only address symptoms, while ignoring the root cause of the problem. Examples include fad diets that continue to contribute to the overfat epidemic, workout plans that increase injury while reducing health, and over-the-counter drugs and dietary supplements that don’t treat the cause and can produce side-effects. Oddly, people continue to believe in these remedies and diets despite clear evidence to the contrary.

Few are spared, including young people, fitness enthusiasts and even professional athletes. The “fit but unhealthy” paradox is seen in those who are powerful enough to perform great athletic feats, but are nevertheless plagued with injury, illness, disease and sometimes even death.

The hallmark of our society and healthcare system is to treat symptoms instead of treating the cause of these problems (or preventing them in the first place). This approach to healthcare is obviously not working.

What is the MAF Method

Our answer to this problem is user-managed health and fitness: each of us takes personal charge to play a more active and precise role in wellness. I invite you to join this process through The MAF Method. It’s a simple concept. First we self-evaluate through an assessment process using surveys to help determine the direction of the second component, lifestyle. Answering key questions can help guide the changes that are most valuable for our individual needs. As a result, we can also learn which supplements, treatments and other additional healthcare components may benefit us.

The MAF Method is a suite of tools and remedies, the culmination of extensive clinical experience, art and science, and feedback from individuals about their experiences. In essence, user-managed health and fitness helps us win the lifestyle game.

The method centers on finding the causes of injury, reduced human performance, illness and increased disease risk, and addressing them directly to substantially improve our health and fitness. In most cases, the primary problems (various physical, biochemical and mental-emotional imbalances) that cause secondary symptoms, are easiest to remedy when better understood and exposed.

Finding a compatible health professional to assist us in this endeavor can also be valuable. In fact, many practitioners use these same tools to gather important information from their clients and patients.

The MAF Method offers a simple, holistic approach to wellness through a better understanding of lifestyle and how it affects our bodies. It’s a way to get back to our natural instincts and intuition humans have always had but too often lose by blindly following diets, off-the-shelf exercise plans or other cookbook, one-size-fits-all approaches.

After almost 40 years of helping individuals of all ages and abilities, and persons with the widest possible array of illnesses and spectrum of personal goals, I’ve yet to find a single best diet or exercise plan that works for everyone. None exists, despite the hype of new books and plans coming out weekly (all of which claim to have found the answer). Instead, the MAF Method offers a way for individuals to address their particular health and fitness needs by balancing food, nutrition, exercise, stress and other lifestyle issues.

Of vital importance to optimal health and fitness is a great aerobic system. With the help of natural, healthy foods and balanced workouts, maximum aerobic function—MAF—helps the body burn more fat and control weight, increase energy and regulate stress, improve physical and mental performance, and eliminate the unhealthy signs and symptoms of an impaired quality of life.

Where to Start

The MAF Method uses primary assessments as the first step in evaluating the body to help prioritize the lifestyle changes that will have the greatest impact. While health practitioners assess with laboratory tests, physical examinations, history taking and other evaluations, questionnaires continue to be among the most important tool. It is also natural for humans to self-assess.

A proper assessment helps bring more accurate actionable steps and faster responses that lead to improved health and fitness. To a large extent, this is accomplished through lifestyle modifications associated with food, exercise, stress and other factors. With a better understanding of the body’s needs, making these primary changes help address the causes, versus secondary changes that include one-size-fits-all diets or other remedies that merely treat symptoms.

The MAF Method’s user-managed health and fitness approach relies on surveys and self-tests, which can provide vital information directing users to make relatively simple lifestyle changes specific to their particular needs. Surveys are in the form of questionnaires, while self-testing includes such approaches as dietary evaluation and exercise heart rate monitoring.

Applying the Method

The MAF Method is simple yet vast because that’s the nature of the human condition. It’s simple because we all must meet the very similar basic benchmarks to be healthy and fit—such as great aerobic function, and natural foods. It’s vast due to all the possible physical, biochemical and mental-emotional factors that influence us, (and because we are all different). Each of us begins the journey to better health and fitness with the first step and from a different point.

The MAF Method addresses three primary lifestyle factors in detail that can most significantly impact health and fitness:

  • Diet and nutrition

  • Movement and exercise

  • Stress and aging

Imbalances in these three areas often result in various signs and symptoms that, at the same time, are clues to the causes of poor health and fitness. For example, too much or too little of certain foods, physical activity or stressors can impair various systems of the body.

It should be noted that the use of tobacco and excess alcohol intake can obviously impair health significantly. One way of tackling these problems is to come back to them after addressing the items below, when your body will be more capable of making the necessary changes.

Users begin with 8 key surveys. These are associated with carbohydrate metabolism, inflammation, the nutrients vitamin D and folate, the aerobic system, stress regulation, the brain, and aging. Answers to the questions lead to a calculation of higher or lower risks, with users guided to take important lifestyle actions to reduce or eliminate these risks. (The term risk refers to signs or symptoms that may increase or decrease the likelihood of a person developing a particular problem, e.g., cigarette smoking is associated with a higher risk for chronic disease.)

The 8 surveys are introduced below, and at the end you are given the option to START with the first survey. In addition to the risk assessment, each step includes links to articles that help direct and support your journey towards optimal health and fitness. You manage the process, and can come back here at any time to take a different route or explore new topics.

Step 1. Regulate Carbohydrate Metabolism:

The consumption of refined carbohydrates and sugar (junk food) is a common primary cause of poor health and fitness. It can lead to carbohydrate intolerance (CI), which significantly affects health and fitness. Early stages of CI are associated with increased intestinal bloating and gas, sleepiness after meals, physical and mental fatigue, and increased body fat. It can ultimately lead to conditions such as high blood triglycerides, hypertension, insulin resistance, and obesity, and even diseases such as cancer, diabetes, heart disease and Alzheimer’s. To begin, take the CI survey by clicking the button below. Your survey answers for this and subsequent steps will determine which articles are most useful for you. You can skip ahead and read more about CI here.

Step 2. Control Inflammation:

Acute inflammation is the body’s normal response to recovery and repair after daily wear-and-tear. Chronic inflammation develops when the body is unable to produce sufficient anti-inflammatory chemicals, often due to a lack of healthy fats or the presence of refined carbohydrates. Chronic inflammation is often the first stage of injuries and pain. Click the button below to take the Inflammation survey. You can also skip ahead and read about chronic inflammation here.

Step 3. Balance Vitamin D:

Inadequate levels of vitamin D has become a serious problem in today’s world. This nutrient, vital for a wide range of health and fitness functions, is best obtained through regular exposure to natural sunshine (while avoiding sunburn). Many people don’t obtain enough sun exposure to maintain healthy vitamin D levels and may need to a dietary supplement. Take the Vitamin D survey by clicking the button below. You can skip ahead and read more about Vitamin D here.

Step 4. Balance Folate: 

A key vitamin called folate helps regenerate cells and regulate a multitude of health and physical fitness factors, including disease prevention. Folate is naturally available in many foods, including certain vegetables and meats. It’s unhealthy cousin, folic acid, is a synthetic version found in most dietary supplements and fortified processed foods, and is shown to have serious potential side-effects. Click the button below to begin by taking the Folate Deficiency survey. You can read more about folate here.

Step 5. Build the Aerobic System:

Maximum aerobic function, MAF, is a key foundation of optimal health and fitness. Improved fat burning is associated with higher levels of physical and mental vigor, injury prevention, increased energy, better endurance and optimal human performance. Those less able to burn sufficient fat must rely more on sugar, and tend to be less healthy with problems such as low energy, increased body fat and weight, less endurance and reduced fitness. Survey 5: Overtraining, as well as the MAF Test, are both subcomponents of this step. Start the step by using the 180-Formula to find your MAF exercise heart rate, which is used to maximally develop the aerobic system. Click the button below to continue:

Step 6. Manage Stress:

Much more than an emotional condition, stress has physical and biochemical manifestations that are just as destructive, if not worse. Physical stress can come from excess sitting, wearing ill-fitting shoes, or muscle imbalance, while chemical stress can come from a poor diet, air pollution, or unnecessary drugs. Regulation of stress begins in the brain and works down into the body. Click the button below to take the Stress survey. You can skip ahead and read more about Excess Stress here.

Step 7. Build a Better Brain:

Various forms of brain dysfunction, including cognitive dysfunction such as Alzheimer’s, result in dependency on others, expensive personal-care costs, loss of ability, and added family stress. Even relatively minor impairments, such as reductions in memory, learning or creativity, are problematic for adults and children. Various dietary factors, easy exercise and stimulating activities such as music and other creative endeavors, can help build a better brain at any age. Click the button below to take the Brain survey.

Step 8. Healthy Aging:

We all grow older, but can control the pace. Various lifestyle factors can make us age faster such as physical inactivity and impaired muscle function, chemical exposure (cleaning products, toiletries, cosmetics, pesticides, chlorine and fluoride) and poor diet are common examples. Virtually all the above steps also impact how we age. Click the button below to take the Aging survey. You can skip ahead and read more about the physiology of Healthy Aging here.


  • hello dr. phil,

    this is christin, the therapeutic yoga teacher from houston again. lol

    love the new site. but miss all the recipes off the old site. i hope they will become available again. i know many of them are tucked away in my copy of your big yellow book.

    so listen. sign me up for whatever you have going on. (actually i already have signed up for everything you have to sign up for on the site:)

    i need your help. please. i feel alone out here in this world of runners doing crazy things with their body and health.

    i have been running ever so slowly with my heart monitor for about 9 weeks, i have done the 2 week test and it has naturally extended to now into its 6th week…i tried putting sweet potatoes back in and they were so sweet i spit it out, i love eating this way, but i am so challenged: i have a foot thing, i have migraines, i live in the city and long for darkness at night and the light of starshine.

    every single day i see myself in my mind, running long long distances, healthy, solitary. vibrantly alive. i FEEL it.

    please. guide me. i am the ultimate student. i am a yoga teacher of many many years and teach that we must live with the beginners mind and i do.

    look forward to hearing from you or anyone on your team.

    go maffetone!

    christin from houston

    • Adam Banks says:

      A balanced diet and reduced stress levels are lifestyle changes which will benefit everyone. Your 180 Formula was really interesting to read about. It is definitely something that is worth a try for those who want to experiment with this method. You will never know unless you try it. How have you measured the level of success with your patients using the 180 Formula?

    • Joei Lo says:

      Hi Dr. phil,
      I m chinese and I m a regular runner, I run around 40Km to 60km a week depending if I have any race ahead or not.
      I found it very difficult to join the nutrition test as I m a vegetarian.
      Without meat. fruit, potatos and some legume, it is hardly to find any carbonhydrate to support my exercise during the week.
      I also started the 180 rules for my regular exercise, which have been started 5 days ago ( which I ran 8km /day), and which I felt less strength, is it normal ?
      Your sincerely,

  • […] am also following the Maffetone Method as from today. With the Scafell Marathon only 19 days away this will be a good benchmarking test. […]

  • Fred says:

    I’m always on the lookout for a formula to help me improve my sub 5 marathon time and your 180 has truly inspired me. I will soon be 66 and have been running quite seriously for a long time. I’ve ran/walked 5 London’s and 1 Berlin since 2010 and my PB is 4:48:57 in 2014. I suffer from Rheumatoid Arthritis in my feet and take some pretty serious medication. My 180 HR max will be 104 BPM (includes minus 10 for my medication). I have been using a HR monitor lately and my easy runs @ 60-65% of my max of 161 are 118-128 BPM. My pace is not fast but I can maintain a steady pace for e.g a 10 miler with not too much discomfort and recovery is pretty good too. If I train at 104 max, I won’t be getting anywhere fast and feel that it will be toooo slow. Could you perhaps comment on the 104 BPM for me? I am in the 3rd week of my next Berlin marathon training plan. What about my weekly LSR? Thanks in advance. Fred

    • Fred,

      As I am sure you have learned by now, MAF is a multi-faceted approach. The 180 formula works best in concert with healthy feet, healthy diet, low stress and a balance lifestyle.

      As for 104BPM, as long as you are on medication it would be wise to stick to this as a maximum.

      Feet: in one of Phil’s podcasts he talks about feet. He also has a 10-step feet therapy guideline.

      As for healthy eating, the two week test would be a great start. Along with burning more body fat, the whole-foods diet supplies food rich in water, also containing the necessary minerals for good health (organic items, that is). In addition, good hydration with local spring water, and pink Himalayan sea salts can improve overall health (including joint health). Try consuming 1/8 tsp. pink Himalayan sea salts per liter of water you consume. this can be on foods, dissolved in the mouth, or in the water! Doing this first thing upon waking can be very helpful. These salts contain over 60 of the minerals needed by the body, often missing in todays food produce. Without these our cells may struggle to uptake fluid, leaving us chronically dehydrated.

      I am not a doctor, I am an avid MAF fan and have had incredible success in health and performance thanks to the MAF method. I wish all other the same or better!

      Good luck!

      Jon Slaney

      • Alan Doyle says:

        Hi Jon,
        do you have a link to the particular podcast where he talks about feet? And the 10-step feet therapy guideline? I’m struggling to find either of these and I’ve been battling with plantar fasciitis for a few years now.


  • Ranjit Nahal says:

    Hi I just want to share my story. Most of my life I have been inactive, used to play football about once a week and Squash now and then. In 2005 on my 32nd birthday weighing 225lbs and my height 5’11 I was in trouble, and I never enjoyed running. So I started jogging, at first just 800m a day, over the next 3 years I built up to 16km every day just jogging. My weight was down 168lbs, still to much fat around my stomach, but generally felt great the only problem was sometimes my sleep wasn’t deep, but I have two jobs and work late Friday and Saturday night and put it down to that. Anyway I started playing Squash again and my friend who I played regular is an active athlete who is a former nation champion at the triple jump, I was beating him on a very regular basis, I was also beating other guys who previously I couldn’t get close to, I just seemed to recover so easily and wasn’t doing any anaerobic exercise except playing once a week. Anyway Julian (the athlete) advised me to start weight training and doing intervals, this was great, as I improved further and got stronger, slowly I became addicted to running hard hills all the time, using a hear rate monitor, sometimes my bpm was over 220. Over the next few years my fitness work was a disaster, nothing but injuries and catching some stupid bug three to four times a year, every time I thought I was making some improvement i would break down.

    February this year I caught a flu bug, in bed four solid days, my weight was back up to 210lbs and I was worried, all that hard work and nearly back to stage one. So I thought back to how I started and how I increased distance really slowly and just jogged. So I started the same again, and jog 10Km a day now, my weight is down to 194lbs, I wear a heart monitor and for 95% of the work out my heart rate is below 140. I don’t feel fit yet, but feel a lot better, enjoy my work outs again, have a lot more energy and feel Im back on track.

    Yesterday I came across this site and thought this method is similar to what I am returning to. I intend to buy your book now and adjust my training after doing your tests and will keep you posted on my progress.


  • Dave Koontz says:

    Wrote about a week ago and got no response. Will try once more.

    I am not a runner, never really have been a runner, and don’t really want to be a runner. But I do like bicycling. I am 60 years of age. Can this program help improve my health and fitness plus maybe help me lose a few pounds?

    Thank you.

    • Dave:

      The MAF method is designed to help everyone all the way up to elite athletes. If you follow the guidelines and calculate your MAF heart rate correctly, then it will do wonders in improving your health and fitness. You can certainly do this method as a cyclist, and you’ll no doubt exceed your weightloss goals if you stick with it.

      • Ranjit Nahal says:

        Hi everyone!

        It’s been 18 months since I last wrote and it’s about time I shared my progress. First I want to point out that during this period nearly all my work outs have been low intensity and last 3 months I have intoduced high intensity once a week. My weight is down to 170lbs, I know it could be lower but my diet lets me down sometimes! I usually run 6 times a week, 3 on the treadmill and 3 outside. When I first started my pace was under 7KPH (133 BPM) and by October 2016 it was 9KPH, however last few weeks my pace has rocketed to 11KPH, I have no idea what has caused this increase so quickly. The biggest improvement though is my immune system, touchwood only had one cold during this time, the method takes time but does work just need to persist.

        Take Care
        Merry Christmas and Happy New Year


  • david lovins says:

    I am 62. I have been training seriously for the past 6 years. a mixture of cardio and weights. In my youth my resting pulse rate was in the low 50’s. I have what is termed a paradoxical tachycardia. I’ve had stress tests & cardiac workups. I’ve consulted with three cardiologist friends as well as four other cardiologists over the past dozen years. Each one agrees I am exceptionally conditioned (for my age). Do I use your formula: 180 minus my age as my training baseline? My recent maximum heart rate was 184 during a kettle bell HIIT session. My resting heart rate runs in the low 70’s.Any activity pops it up into the low 90’s.


    • David:

      Thanks for commenting. While you may be exceptionally conditioned, many exceptionally conditioned individuals (such as Mark Allen, Mike Pigg and other elite triathletes) had a very poorly developed aerobic system, before adopting the MAF method. Developing that system is what the 180-formula is all about. For example, one of the reason many people have swings in their energy level is because their aerobic system (which burns fat) is so poorly developed that their anaerobic system (which burns sugar) has to make up the slack just to keep them going on the day-to-day. Sugar reserves drop, and either their energy plummets or they get cravings for sugary foods (or both, as is usually the case). This, of course, typically ends up being a huge health problem. Training the aerobic system so that it can sustain the body on fat reserves means that the body needs to burn less sugar for fuel, at least in every day activity.

      The aerobic system also helps recovery from anaerobic workouts: the mitochondria (which are the aerobic motors of the body) process lactate, the by-product of anaerobic exercise, convert it into CO2, and allow it to be expelled from the body through the lungs. The more developed your aerobic system is, the better your recovery from anaerobic workouts will be.

  • Dave says:

    Had knee surgery following an accident last year. Just returning to running. I understand the 180 method, but can not find a recommendation on building up the running time? I see different plans by others, but curious on Dr. Phil’s thoughts?

    • Dave:

      Generally, whatever feels good.

      Some people start by doing a 15-minute warm-up followed by a 15-minute cool-down, just to start practicing the movements, 5 times a week. they do this for 1 week, and slowly start adding time at MAF pace. The 2nd week you might be doing 10 minutes (for a 40 minute total), the next week do 20 minutes (for a 50 minute total) until you get to (~1 hour) of MAF pace, 5 times a week.

  • jenna says:


    I had posted a question but it looks it never went through so I will try again!
    I am new to this so it may be a silly question, during the warm up and cool down, what should be my HR? Just lower than my MAF pace? My MAF is 152. I used this method on my run last night and left feeling with the most energy i have had in a long time! Looking forward to this! Thanks for your help!

    • Jenna:

      I apologize if your question went unanswered. It’s a pretty important one, but not one that you have to worry about too much. Usually, it’s best to warm up 20-30 HR below your MAF pace. For example, my MAF HR is 149, and I’m going at a brisk jog (8:40 mile). So I warm up at a fast walk (something like 115) and jog slowly for the last 5 minutes, bringing my heart rate up to the mid-130s. In other words, I try to scale it up as I warm up. For the cool down I do the same.

      Remember, it’s a lot more important that you warm-up and cool-down than exactly how you do it, as long as it follows a gradual curve as it rises and falls.

  • Chris Lawson says:

    Love the new website
    I’m racing an Ironman in a few weeks and have developed a decent base and reasonably fat adapted. Should I do the bike at MAF (139) and just go on feel on the run?
    After my race I intend going back to MAF for 2016

  • Craig says:

    I read an interview form one of the success stories where the recommended maximum training time for the marathon was 2 hours. Is there a similar view to limit time cycling to 2 hours? Some races are 3-5 hour events. Should some of my training at MAF rate last as long as the event?

    • Craig:

      To be ultra specific about it, you start getting diminishing returns for your training at just under 2 hours. For people that are busy, or even athletes that are very good at workout specificity, it’s good to know that there’s a lot less bang for your buck after 2 hours. The most important thing about training vs. event, is to know 2 things, in this order of importance: (1) have a knowledge of race time, and (2) have a knowledge of race pace. Your training should help you figure this out somehow.

      That said, it’s a lot less important to train in the sense of “getting yourself tired” at race pace, than to know your race pace, in the sense of “getting a comfort and understanding” of race pace.

  • Carl Lofthagen says:

    Hi there! My name is Carl, I’m 21 years old and am a collegiate rower. I found out about the Maffetone method recently and found it really interesting. I really see how it benefits long distance running and prevents injury. The 2 weeks test also totally makes sense! My question is whether this sort of training is relevant to a sport like rowing. Races are usually about 6-6.30 min long (much shorter than any running race) and you row at pretty much 90 percent capacity the whole way. Will training with the 180 method help also with high intensity races and is the no sugar plan still effective? I know it may seem a bit difficult to know but i would love any opinions on the matter!

    • Carl:

      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.

      When you are training intensely, however, you may need more carbs than the two-week test allows for.

  • […] experimentó el proceso de cetoadaptación, trabajando directamente con el método Maffeton, seguido por triatlonistas legendarios como Mark Allen, seis veces campeón del IronMan. Consiste […]

  • RunMAF says:

    When running a marathon what is the recommendation for eating energy chews? Also if you want to run to a heart rate ina marathon what is suggested? My MAF is 135. Thanks

    • RunMAF:

      Our recommendation is for you to train your aerobic base up to a point that you run a marathon at the same pace with or without them. Since marathons should be aerobic events, the fact that you need energy chews (which have sugar) means that you are using anaerobic channels (which burn sugar).

      That said, if you must use them, eat one (100-150 cals) every half hour.

      Your marathon heart rate should be 10-15 BPM above MAF.

      • RunMAF says:

        Thanks. I have been doing MAF for just over 2 months and will be close to 4 by marathon so I am assuming I will not have the aerobic base not to take chews by then and will still need them. Any way I can tell?

      • RunMAF says:

        For pre-race meal for marathon what do you recommend? Phil’s bar or shake or something else. Thanks

      • Joe says:


        I appreciate your responses to so many comments on here, but I have to share that your comment about sugar is confusing and wrong. The body will always prefer the use of sugar to fats as intensity increases because more ATP can be generated per unit oxygen when burning glucose vs. burning fats. To state that someone needing to take energy chews indicates they are using anaerobic channels is false – the body is always burning a mix, and performing at the % VO2max that you will be in a marathon, your body will be using a considerable portion of energy from carbohydrate. If you run a marathon with no nutrition, you likely aren’t performing at your full potential.

        There is, in fact, significant evidence that carbohydrate supplementation during prolonged (>2 hr) endurance exercise improves both time to exhaustion and average speed. A cursory search of PubMed will yield a plethora of results.

        • Joe:

          What you say is true, but the mark of a very fit body is that it is burning a greater percentage of fats at higher intensities because it has a more developed aerobic system. The better the endurance athlete, the more fats they are burning at any given percentage of Vo2 Max. The onset of blood lactate accumulation (due to the onset of systemic anaerobic activity) marks the peak in the rate of fat oxidation (due to the fact that lactate is a potent inhibitor of lipolysis). For this and other reasons, the onset of anaerobic activity is a threshold for the body’s metabolic fuel use: as long as systemic anaerobic activity is minimal, the body could potentially be oxidizing more and more fats (as long as it has the capability to do so). But at the onset of systemic anaerobic activity, the body is forced towards increased sugar utilization due to subsequent reductions in lipolysis. So while eating energy chews is not a direct indicator of anaerobic activity, a greater need for sugar supplementation directly indicates an increased likelihood of anaerobic activity.

          The reason I say that the body “prefers” fats to sugars is because sugar-burning increases and fat-burning drops in direct relation to the increase in systemic circulation of stress hormones. Laursen et. al. speculates that the peak of fat oxidation, due to the fact that it marks the onset of systemic anaerobic activity (e.g. the aerobic threshold) also marks a threshold of physiological disturbance for the body: “…the first ventilatory threshold may be an important demarcation point identifying the training intensity above which autonomic balance may be altered.”

          Below the aerobic threshold, the body is able to oxygenate all of its functions ad infinitum, whereas going above it marks the point at which all functions are not fully oxygenated. So to speak, as soon as the body crosses the aerobic threshold, it’s only a matter of time before it has to drop back below the aerobic threshold to restore full oxygenation. In other words, crossing the aerobic threshold marks a significant qualitative shift in the body’s ability to maintain homeostasis.

          The fitter body is, of course, the one who can remain at a greater homeostasis given any level of athletic demand. Dr. Maffetone’s own research lends evidence that an increase in fat oxidation correlates strongly with a decrease in need for dietary carbohydrates, an increase in race speed, and an increase in health. All of this can be chalked down to the fact that the athlete is in a less metabolically-disturbed state at a higher athletic demand, which also corresponds with comparatively higher fat oxidation. Fundamentally, we can also say that a better athlete is one who needs fewer carbohydrates at a higher Vo2 max (because a greater percentage of their energy needs are already being supplied by fat).

          While supplementing with carbohydrates has been shown to increase speed and endurance, insofar as the body can fuel a greater percentage of its energy needs (at a greater percentage of Vo2 Max) with fat, carbohydrate supplementation will be superfluous (as it is attempting to meet an energy need that is already covered). The less energy chews you need at any given intensity, the better an athlete you are. Building that athlete is what we aim for here at MAF.

  • RunMAF says:

    I will have been doing MAF training and for about 4 months when I race. I’m assuming I will be a long way from fully developing my aerobic system. Does that affect the energy chew question?

    • Not really. I just wanted to provide you with a few more guidelines and an idea of what needing energy chews means. As long as you marathon responsibly without breaking your body, and seek to develop your body to the point where you can run the race in a predominantly aerobic mode, then you’re doing the right thing!

      • RunMAF says:

        Thanks. How do you recommend to fuel during the race? Aside from water what solid food/ other liquids ?

        • The “problem” with solids is that your body has to divert blood away from the muscles in order to digest better. However, many people (including myself) have had success with Phil’s bars, or even guacamole-tempeh burritos on very long runs. The best thing you can do is figure out what are the extent of your nutritional needs (particularly in terms of carbohydrates) and go from there.

          There’s no way to give you truly specific guidelines, because everyone’s different.

          • RunMAF says:

            And aside from water, what types of liquids do you recommend, if any? thanks

          • Honestly? Water, water, and water. A 3-6% carb solution is good for racing, but whether you are adding carbs, protein, or fats, that’s still stuff that you personally add onto water. Performance drinks often contain too many carbs for the body to maximize aerobic function (and if your race has a strong anaerobic component it should be short enough that you don’t need to drink anyway).

            Hope this helps.

  • Nathan says:

    Hi, I’m very new to this and am keen to trial the Maffetone-Method. I have a couple queries though:
    The method states that fat burning improves mental vigour, but doesn’t the brain use glucose from carbs as it’s primary energy source?
    Hi fat low sugar, to my mind, means high protein too. I thought studies of high protein diets in rats showed it lead to increased disease and reduced lifespan (not sure where I heard/read that, nor the details of the study, sorry).
    Is there any risk of loss of muscle mass using this method, as the body hunts different energy stores? Does this matter?
    The Method doesn’t discount carbs altogether but how does one figure out the right personal balance? Is it just a matter of trial and error?

    • Nathan:

      You’re right about glucose and the brain. But think of it this way: the body never really burns fats. What it does do is convert fats to glucose, thanks to the presence of oxygen, which it then burns. So, if you aren’t good at burning fats, you might need to dip into your liver and blood glucose to power your body in addition to your brain. This will mean that your blood glucose will drop, and you’ll experience cravings for sugar, as well as swings in your energy level. But on the other end of the spectrum, if you’re a very powerful fat burner, you’ll be able to power both your body andyour brain exclusively with glucose converted from fat, while using stored glycogen onlyto get that fat-burning process going. While you’ll still need some carbs to get that process going, your brain will still be much more consistently fueled.

      Well, it doesn’t need to mean that. But one of the problems with those articles is that while they may be relevant to nutrition alone, the result may actually be completely different when you are living an athletic lifestyle. (We humans are endurance machines—we’re supposed to be highly active). That said, protein toxicity is a thing. You really shouldn’t go above 40% protein in your diet, and most people don’t really need more than 20. But if you have a high turnover (use) of muscle fibers, you’ll be using a massive amount of protein anyway.

      Where this diverges from the study is that it’s unclear whether those rats had easy access to exercise, and whether the amount of protein they were fed coincided with the amount of protein they need, due to muscle protein turnover. Everything is a matter of thresholds: a lot of water isn’t the problem. Too much water is. A lot of protein isn’t the problem, and neither is a lot of carbs. The question is, how much is too much. And when you consider that we should all be living a highly athletic lifestyle, it’s hard to know when “a lot” will become “too much.”

      There is always a chance of losing muscle mass, although if you teach the body how to burn fats (rather than just restricting carbs) the body won’t have to turn to protein for energy. That said, the important thing about muscle isn’t whether you have a certain amount; the important thing is whether what you have is doing something for you. For example, if you are lifting heavy weights, it’s highly improbable that you’ll lose mass, and if you do, you probably won’t lose strength.

      (Strength comes from the amount of “voltage” that goes from your brain, through your nerves, into your muscles, not the muscle size. The reason muscles grow in size is that typically, but not necessarily, bigger muscles can accommodate more voltage. In other words, the correlation between muscle size and muscle strength, while causally connected, is indirect: muscle size and muscle strength are only related because they are related to the power of your motor neurons).

      Finding the right balance of carbs is a matter of trial and error. That’s why we continually recommend that people do the Two-Week Test. As you begin to incorporate carbohydrates back into your diet (once you finish it) it will become immediately apparent to you how much is too much. In other words, the Two-Week Test makes the process of trial and error very easy to manage.

      • Nathan says:

        Many thanks for such a detailed response to my queries. My heart rate monitor has been ordered and I’m eager to begin!

      • Joe says:

        This is wrong as well, Ivan – you need to check your biochemistry – while a single triglyceride is broken down into a glycerol molecule and three fatty acids, only the glycerol molecule has a chance of being converted to glucose – the three fatty acid chains cannot be converted to glucose and thus are burned via separate processes.

        • Joe:

          Thanks for your comment.

          I was using “glucose” as a stand-in for Acetyl-CoA, which the fatty acids eventually turn into in order to be processed in the citric acid cycle. It’s wrong, but I used it in an attempt to avoid getting deep into the biochem of it.

  • Amir says:

    I’m 58 years old, and started training regularly just 9 months ago, with the sole purpose to gain health and get rid of medications I’m on for the last 10 years.
    The first months I’ve followed the instructors at the gym, with emphasis on various weight machines, and injured myself a couple of times. Alongside I did some “aerobics” on an elliptical trainer, round 40 minutes on HR of 80% of my max HR.
    Overall, I haven’t felt much better, with no better blood tests results.

    A week ago I’ve stumbled upon Maffetone method. Got hooked immediately, since it made much sense to me and my perceived needs. Just calculated my proper MAF HR according to the 180 formula (turned out to be 112), and finished the first week of five training sessions on the elliptical trainer of one hour each (15+30+15), and never felt better. Now I’m on a two days rest (that are mentally hard for me). Still, I’m currently left with two unanswered questions.

    Today I made my Tai-Chi sequence with my HR monitor on. I’ve noticed that my HR was high above my MAF HR – just 2:30 min on the aerobic zone, then 2 min @ zone 3 (113-130), followed by 22 min @ zone 4 (131-146) with a 50 sec peak with max HR of 149.
    My question is whether weakly sessions like this may ruin my effort of building a proper aerobic base? Naturally I prefer to keep on with these sessions alongside my MAF training.

    My second question refers to the MAF test – the gym Treadmill’s units are set to metric. Is there a minimum time for the actual test to be valid (or min of 3 miles), or doing it over 3 Km (currently, with a somewhat reduced HR of 105, takes me around 11 min/Km) is good enough?

    Thanks, and looking forward to the iOS app!

    • Amir:

      A weekly session with those heart rate measurements shouldn’t ruin your efforts, but you also won’t be building your aerobic base as quickly as you possibly can. It’s fine to keep that in your training, unless you are injured, ill, or overtrained. If you are, I’d recommend doing exclusive MAF workouts for a few months. The 3 KM MAF test should be enough, but if you can bring it up to 5 that would be even better.

      • Amir says:

        Thanks. I can keep on without any guilt feelings 🙂

        One more question: what about a decent Espresso / black coffee before MAF training session? Seems that the expected published benefits are in tension with the elevated HR caused by caffeine, is it?

        • About caffeine, yes, basically. And Amir, I don’t mean to be dull or annoying, but I believe that thinking of it in terms of “guilt” or “not guilt” truly is counterproductive in the long run. Depending on your situation (which you can tell by your MAF test) there will be good effects or bad effects. Feeling guilty isn’t the price for making a bad athletic decision—it’s usually your knees, your heart, or in the case of serious overtraining, your future athletic ability. Whether you should feel “guilty” towards us or towards yourself can trick you into forgetting to pay attention to how the exercise you’re doing is affecting your body. That’s what’s important.

          Don’t choose one exercise or another because we tell you to. We’re not judges and we won’t hold you accountable. If you look at your MAF test and see that you’re plateauing or that your MAF speed is decreasing, your guilt (or lack thereof) is the least of your worries.

          That said, if you do consistent, monthly (or bi-weekly) MAF tests and tally your results, you can know whether you’re doing the right thing.

  • Kirsty says:

    Can I continue to do yoga while I build my aerobic base? I am a pretty active person and am wondering if I need to curb my physical activity generally or just ensure that I’m keeping my heart rate in check at all times (yoga, hiking, bike riding etc.)?

    • Kirsty:

      You may already have an aerobic base well-built, particularly if you have been consistently athletic without injury. Figure out your MAF heart rate (check out The 180-Formula and figure out your MAF heart rate). Do a MAF test (15 minute warm-up, 3-5 miles at MAF) and then 15 minute cool down. Most people find that running at their MAF heart rate feels very, very easy (and that their MAF speed is very slow). If running at your MAF heart rate feels relatively difficult (and you’re fast), then you know that you have a pretty robust aerobic base.

      That said, for just about any athlete across the board, 80% of training should be done at the MAF heart rate or below.

      I hope this helps. Please shoot back with any more questions.

  • Michelle says:

    I am a road cyclist currently training for an endurance event on 25 October. It’s 255km with 5000m of climbing. I have only recently heard about the Maffetone Method, but I had learned of aerobic base training earlier this year and so I incorporated 3 months of base training at the start of my training this year (low HR / high cadence) before recently switching to my ‘normal’ 12-week training program the last few weeks. This includes hill repeats, long training rides on the hard hills of the course, interval work, etc. I have been less concerned with keeping my HR down since switching into the 12 week phase of training, although I notice the base training has had a positive impact as my average training HR is now lower than it was last year. 🙂

    Now I have discovered MAF, it seems you would recommend I continue to stick with training at my MAF heart rate 80% of the time right up to the event – even on all my steep hilly training sessions, which would mean slowing right down for those? To meet the 80% rule, I would also have to drop some of the more intense workouts I am doing (like the intervals). Do those athletes who have just started with your method find they can train effectively on less hilly terrains (in order to maintain MAF HR) but still do OK strength and speed-wise on steeper/more hilly events? My concern is that if I revert to MAF heart rate now I won’t develop enough strength endurance (and speed) if I don’t do adequate amounts of training over long distances in steep terrain. Although, now I’ve read your material, I’m also concerned if I stop paying close attention to my HR I am daily eroding the lower-HR aerobic benefits I just spent 3 months building up!

    The event I’m doing has a time limit, so I cannot afford to lose too much speed. Is 10 weeks enough time for me to slow right down again on the hill training so I stay at my MAF and gradually build my speed back up while staying within MAF HR? Or is it too late now for this particular event?

    • Michelle:

      Endurance events are overwhelmingly aerobic events. What this means is that if you don’t preserve your aerobic base, you’ll lose the endurance capabilities you are counting on for this race. Above all, preserving your aerobic base is imperative. How do you do this? By using the MAF test as a diagnostic tool: test every 2 weeks on the same flat surface, in the same conditions, for 5 miles, after a 15 minut warm up. If your MAF speed plateaus or begins to drop, your aerobic base is deteriorating.

      Another point: Much more important than being able to maintain your speed on those hills is your ability to recover from them. Your aerobic base will help you a lot more in that than your anaerobic power. Drop your intense workouts to stick to the 80/20 rule. They just won’t do for an endurance event what your aerobic workouts can. The best way to do it is to make your long bike rides flatter, to stay at MAF at a higher speed, and to make your hill workouts 20% of your training.

      Let me state this in the simplest possible way. Doing more anaerobic training (and having to fuel yourself with high-carb foods) may make you faster today, than training the MAF way. But what it will also be doing is eroding your health and your aerobic base, ultimately compromising your ability to train and be faster still for your next race. Training aerobically right now may make you a little slower today but a lot faster tomorrow.

      I hope this helps.

  • RunMAF says:

    In terms of pre-race marathon meal do you recommend the Phil shake?

  • Brad Dre says:

    I’ve been training on bike for 30 minutes per day for 2 months at 120 heartrate, which is about 5 bpm below MAF. I’ve done an aerobic fitness test 3 times and my times have gotten slower and stayed the same. I’m willing to be patient and keep at it, but I have two questions about the training and testing: 1) should I expect to see some improvement in aerobic fitness after 2 months? I exercise about 6 days a week, and 2) does the test activity need to be the same as the training activity? My test activity is 1600 meters running on a track and I’m training on a stationary bike. My bike is not able to measure power or distance accurately. Thanks!

    • Brad:

      Yeah, the test activity does need to be the same as the training activity. For example, the reason your very real aerobic gains may not show up in the running test is because your body has to optimize itself in a very different way: it needs to have very powerful shock-absorption and stretch-shortening reflex abilities, which you don’t really cultivate on the bike.

  • Martin says:

    Hello everyone,

    I am 45 and I started the MAF HR method (180-45=135) yesterday. It’s been a real pleasure to run my usual 5K! However, I have a question: I am taking high blood pressure medication and Cipralex (antidepressant). Should I subtract another 10 to the usual formula?

    Thanks for your reply!

    • Martin:

      Yes, absolutely. Any medication has a powerful influence on the hormonal system (since that’s what most are meant to do). Since hormones are what controls the amount of aerobic versus anaerobic activity, it’s necessary to subtract those 10 BPM.

      It’s important to be conservative. For example, I haven’t been injured in quite a while, but I have some hip muscle imbalances that I’m addressing. I’m 27, so my 180 – Age is 153. However, I’ve also subtracted 5 for the muscle imbalance, so my MAF HR is 148. In a couple of months, I’ll bring it back up to 153.

  • Martin says:

    Dear Ivan,

    Many thanks for your quick feedback! 126 BPM seems unusually low but I will incorporate this in my routine.

    • Martin:

      This is about training your aerobic system to catch up to your anaerobic development.

      By training at this heart rate, you enable developing the aerobic system at the exclusion of the anaerobic one. Although you may be burning fewer calories per hour, the important part is that this is the only way of developing that particular (and highly important) part of the engine without breaking it down faster than you can repair it.

      In other words, this is specificity of training. We don’t just want to make you “fit” in some vague sense of the term. What allows you to maintain muscle mass, maintain energy, maintain health, and create endurance is literally the power of the aerobic system. We can’t get to that at a higher heart rate.

      The only reason that this is unusually slow—and it is an important one—is because the overwhelming majority of westerners (myself included) have a very poorly developed aerobic system, because we are incorrectly accustomed to doing the overwhelming majority of our training at a higher heart rate. To give you an idea of how important running at an aerobic heart rate is, it is said that a Kalenjin (Kenyan) youth has run 10,000 (that’s ten thousand) easy miles by the time a western youth has started high school. Go figure.

      I needed a lot of motivation before being able to run 2min30sec slower than I usually did. But the method works.

  • RunMAF says:

    Hi. I have improved my MAF test by about 1 minute per mile in 4 months so I know it works. However, in marathons i have struggled because my legs can’t cope. I think I need to do some strength/weight works as well. What do you recommend?

    • RunMAF:

      Could you describe to me what you mean by “my legs can’t cope”? Thanks.

      • RunMAF says:

        Getting very bad cramps especially in the calves. Around 20 miles. Heart rate was 10-15 bpm above MAF until that point.

        • RunMAF:

          I can’t really give you any good advice, other than go to a gait specialist. Speaking generally, it’s a bad idea to prescribe correctives without a comprehensive physical exam: it’s difficult to say if the issue is mechanical (in the muscle and joint), sensory (in the way that information is processed) or motor (in the way that the brain thinks it should go about applying this information).

          Also, speaking specifically, it’s almost impossible to prescribe correctives without a physical exam when the problematic area is closer to the ground. The calf muscles in particular have to work with a lot of other muscles to provide the necessary mobility and stability in the movement in question: hamstrings, frontal calf muscles (peroneals and tibials), quadriceps, glutes, etc.

          For that reason, any problem that shows up in the calf muscles may have nothing to do with the calf muscles themselves, or a lack of strength in the calves, and everything to do with stuff that is very far away and seems “unrelated” to the untrained eye. Let me give you 2 great examples of this:

          1) Sometimes, a problem that originates in the neck (such as a head that is thrust too far forward of the body) can change the alignment of the shoulders and hips in such a way that the hamstrings and the calf muscles can’t work together anymore.

          2) One of the most important job of the calf muscles (specifically the soleus) is to pump blood back up to the heart. When the heart gets fatigued, the soleus can start working overtime in an attempt to maintain blood pressure (although this is rare). Conversely, when the soleus gets fatigued, blood pools in it (hence the cramps) and the heart rate has to increase to maintain blood pressure.

          Either way, it’s hard to know whether the soleus is fatiguing, 20 miles is the present limit of cardiovascular endurance (or alternately, aerobic endurance), or there’s a deeper motor/alignment issue that must be dealt with.

        • RunMAF,

          I find your post interesting. Already some great comments, Ivan. Please allow me to add to the discussion.

          1.) First try and find if there is a nutritional imbalance, such as mineral deficiency or imbalance.
          – If this is the case, then dissolving sea salts on the tongue during this time of legs can’t cope” may signal that the item of deficiency is now present, and it is okay to carry on. If this is your issue you will notice an improvement.
          – In terms of macronutrients, it could be an issue of carbohydrates. An athlete who is well trained and relies on mostly fat in the muscle will still benefit from a small amount of carbohydrate solution to support fat burning, brain and nervous system function. If this is your issue, even the sensation of carbohydrate solution in the mouth may be enough to void the issue (try honey and spring water). Similar to above, the brain provides a signal that previously limited nutrients are now plentiful.

          2.) Second I would suggest looking at the feet. Phil’s foot therapy (10 steps) is a great start. If this is the issue, an intervention to spend some time barefoot could have a dramatic impact on foot function, lower leg strength, and whole body posture. Often times perceived a cramping/angry soleus may be the actual result of a weak Flexor Digitorum Longus of the foot and posterior lower leg. This may occur after use of over cushioned/protective footwear.

          Jon Slaney

          • Jonathan:

            Thanks for your input.

            While these are all good points, I didn’t want to speculate on them in that way. My reasoning:

            Cramps in the calves are a local problem. Whether they be derived from weak muscles, muscle imbalances, or mineral deficiency resulting in nervous system issues, the point is that this mineral deficiency isn’t systemic: the calves have been using up (usually potassium) faster than the rest of the body. The gait problem that leads to this use differential is the real problem. If we band-aid it during a race with more potassium or calcium, we are enabling a tissue that is by definition not strong enough (or not synchronized enough) to run that race. At the end of that race we may come to realize we created a bigger problem.

            Again, I would say the same thing about limited nutrients: while the signal you mention is real, the BIG problem is that one particular area of the body is being disproportionately affected by that signal (the SMALL problem being that the signal is occurring at all).

            That said, I completely agree that going barefoot is an excellent fundamental corrective to these problems—I’m just pushing back a little on the other issues because I’d rather not have a runner band-aid the problem without the supervision of a coach or a health specialist. If I was talking to (someone I knew was) a coach wanting another kit in their toolkit to apply on a discretionary basis with their athletes, my advice would have been very similar to yours.

            That’s why I would rather direct this person out to an expert that can give them a fundamental solution specific to their situation.

  • Ketorunner says:

    Dear Ivan,

    I tried submitting a comment and I think it didn’t get through so I am trying again. Apologies if you got this twice.

    First of all, I would like to thank you for all the great advice you have given to all our questions. I have read most of the posts and have learned a lot.

    I am 59 years old and have been running for a long time. Six months ago I started a LCHF (low carb high fat) diet. I was skeptical at first but the benefits have been quite amazing. Not only has my overall health improved, but I am running better now than ever before.
    I am currently training for my 4th marathon which will take place in October. My heart rate, based on the MAF formula is 126. 180 – 59 =121 + 5 = 126.
    I would like to do one more LSD run of 18 miles before my race. However, staying at 126 bpm will take about 3 hours to complete since I will be averaging 10:00 minute miles unless I increase my heart rate. My concern is the amount of time I am spending on my feet may do more harm than good. Is this a case of diminishing returns? Please let me know what advice you can give. Much appreciated.


    • Ketorunner:

      Thanks for commenting. I did answer your comment, but I’m re-posting it here:

      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.

      • Ketorunner says:

        Thank you for the feedback, Ivan. I will go ahead. My marathon is on October 17th, how many more long runs do you suggest before then?


        • Ketorunner:

          I’d say do 1 every 10 days (ish), leaving a full 10 days to taper for your marathon.

          • Ketorunner says:


            Thanks again.
            Over the past few months I have discovered some things that has helped me to keep my MAF HR at or under my respective BPM. If you don’t mind, I would like to share them with others in case they may help them also.

            * Try not to run on busy streets – cars, exhaust fumes and noise increases stress. Find a park or trail even if it means driving somewhere.
            * Breath slowly, inhaling through your nose and exhaling through your mouth.
            * Run as smooth and efficient as possible. Notice how your feet hit the ground, your stride and turnover. And remember that it’s not about speed. You want to be as calm and relaxed as possible. Your run should be a pleasurable experience.
            *Be aware of your surroundings – the landscape, the weather. Feel the warmth or cool air on your skin. Listen to the different sounds around you.
            * Stay focused. Don’t think about anything in particular. Especially negative thoughts or something that is bothering you. That will shoot your heart rate right up. Let thoughts just drift in and out.
            * Finally, know why you are going out for a run. Have a plan. Maybe you are going out for an hour or you want to do an easy 8 miles. Whatever it is, stick with the plan, you will feel a sense of accomplishment at the end.

            All the best!

    • Ivan, thanks for bringing this up. My advice is not complete without an additional aspect.

      Once the problem is found (let it me muscle imbalance, salt, exogenous carbohydrate, lack of aerobic base to exceed 20 miles, etc.) the doorway to the solution is just beginning. This is why I suggested each of these interventions. If an intervention is effective (a Band-Aid, well put) it then gives much insight into what needs to be corrected in daily life in order to prevent that further issue.

      For instance:

      Salts/minerals. If the brain is successful in reducing the local muscle issue through nerve innervation, then there may be minerals (or mineral absorption) missing in the daily diet. Adding these during regular meals and to drinking water can then provide a solution, but only to be re-tested until the problem no longer exists in order to determine the effectiveness of the intervention. The intervention here would be adding the minerals to the diet (could add all trace minerals in this case, a likely deficiency in the modern diet) and then re-try the run. If the 20-mile issue persists, it’s onto another possible intervention. If it does not persist, continue to add these minerals to the diet and enjoy your marathons to the fullest.

      The same can be said for exogenous carbohydrate, except in this case simply finding the amount during the event will be the resolution, a true story for many athletes.

      As well for muscle imbalance, if this is corrected and the problem persists, it’s time to keep looking. If the issue goes away after barefoot therapy, then happy running!

      Basically what I am trying to promote is: assess + find the issue + determine a solution, intervene, and reassess.

      • Jonathan, I’m revising my previous agreement with your comment.

        I agree with most of what you’re saying, except with the mineral issue. Replenishing minerals through the diet can’t be a fundamental solution, except in the cases where you see generalized, systemic muscle cramps (as in the runner who cramps in say, the quads, calves, lower back, deltoids, and pronator teres—which is my least favorite muscle to cramp—simultaneously). If the problem is systemic, then like you say, the problem can be carbohydrates, salt, a lack of aerobic base, but it’s less likely to be due to muscle imbalances—because it’s showing up across an array of muscles.

        If the problem is localized, while you can eliminate the symptoms by increasing carbohydrates or minerals, you’re not really going to solve the underlying issue until you deal with that muscle imbalance. If adding carbohydrates of minerals does indeed clear up the symptoms, you may be masking a deeper problem: why the cramps showed up in the calves and not elsewhere. You mention that you should “re-test” until the problem no longer exists. But in the case of localized muscle cramps (as opposed to systemic, generalized muscle cramps) the BIG problem wasn’t a lack of minerals or carbohydrates—that’s the SMALL problem—but rather a muscular imbalance that leads to stiffness or overuse of those particular muscles but not others, due to a disparity in the either consumption or supply of energy or minerals.

        I agree with the assessment formula you present at the end; however, I disagree emphatically with framing either localized muscle cramps or lack of salts and minerals (in the case of localized, but not systemic, muscle cramps) as “The Problem.”

  • botroxy says:

    My MAF number is 141 and I can’t stay there or under it without walking the entire time! Will walking eventually lead to running?

    • Botroxy:

      Yes. Your aerobic system simply can’t produce enough energy to run at this point. Specifically, the most important thing that you need to be able to do to bridge walking and running is to use your hip and leg muscles to absorb the shock of landing during running without resorting to the anaerobic system.

      I recommend jumping rope (staying at or below MAF) for 10 or so minutes a day to help bridge this. (Some of the stresses from running, that necessitate anaerobic function, come from forward travel). Jumping rope eliminates this, while developing the shock-absorption component of running.

  • Stephanie Jamrog says:


    Would exercises like yoga be a hindrance when trying to build aerobic fitness?

  • Wouter says:

    Hi there,

    I am very interested in the MAF method, and see many similarities with MET (Metabolic Efficient Training by Bob Seebohar). MET indicates that after a while, you can run with a high heart rate and it will still be in your (new) aerobic zone. With the 180-formula I get the feeling that the aerobic zone is more static.
    Is that a different philosophy, or something I misunderstand in MAF?

    Looking forward for your repley and the app!

    • Wouter:

      I haven’t heard or read much about MET training, but I think that it may relate to this: The lactate (anaerobic) threshold tends to rise to a higher heart rate with more training. However, that doesn’t mean that you should spend more of your training at that higher heart rate—it just means that when you do anaerobic threshold training, it should be performed at that higher heart rate.

      The anaerobic threshold isn’t when anaerobic function starts, but rather when it outpaces aerobic function. That is the number that changes with more training. What doesn’t really change is the moment when anaerobic function starts (also known as the aerobic threshold). The MAF method is all about performing the overwhelming majority of your training at or below the aerobic threshold.

      • Wouter says:

        Hi Ivan,

        Thanx for your feedback.

        Yesterday I started with MAF, and ran my reference lap on an almost flat (only a few bridges to cross) round of 7 km. I was a bit surprised with the results, running close to a HR of 140 (as I’m 40 years). The last km is only 4 seconds slower than the first and only when I had to cross a bridge my km-times are a bit slower.
        I wonder how this will evolve during the next weeks/months.

  • Ketorunner says:

    Hello Ivan,

    I was having a nice LSD run today and it occurred to me that I have been training incorrectly for many, many years. Like a lot of runners, I would start off slow to warm up and then run pretty hard for 6 miles. This was was my routine for a long time. I had no idea what my heart rate was because I never used a heart monitor, but I bet it was in the 160’s. BTW, my MAF heart rate is 126.
    So, my question is: has this done any harm? And if so, is it reversible? I obviously never fully developed my aerobic system since I was running mostly anaerobically. Please let me know your thoughts.

    Thank you,

    • Ketorunner:

      The body grows like a weed that never let go of a grudge. It’s a high-performance machine that was designed to compete with the lion and the deer and the sun and desert and the cold. There are so many negatives encroaching on the body’s ability to grow, that usually as soon as you remove the negatives, you really start seeing the body take off. (In particular, you see this in physical therapy for athletes: there is usually one of two exercises that are causing the damage you see. You remove those, and strength or performance issues in a whole bunch of places just evaporate).

      So it’s not so much that you have to “reverse” the problem—unless, of course, you have an array of severe medical conditions—but that you just have to remove the stops and let the body do its thing.

      MAF training (and in particular, following the MAF lifestyle) does exactly this.

  • Ketorunner says:


    Thanks for the quick response.

    I do agree with you; and we have definitely lost our way in this “modern” world. BTW, I don’t have any medical conditions and have never been injured except for minor aches and pains from over doing it a bit.

    Could you elaborate a little more on what you meant by damage caused by physical therapy? And what you meant by “stops”.

    Thank you,

    • Ketorunner:

      Thanks for your comment. I didn’t mean that physical therapy itself caused the damage, but rather that the solution often doesn’t lie in applying therapy to the joint or limb in question, but in removing a particular activity that the joint was performing in an injurious manner. Generally speaking, this is what I mean by a “stop”—anything that blocks the body from development. Another stop would be cheat meals, or bad sleep habits, or a particular work environment. This tells you something about a lot of chronic diseases: they don’t occur typically because the body is being damaged but rather because it is being sufficiently prevented from developing that it can’t recuperate from the basic stresses of life. It’s no longer able to break even.

      • Ketorunner says:


        Thank you.
        I think I understand what you meant now. So by not fully developing my aerobic capacity all these years because of running above my aerobic heart rate (essentially running in a anaerobic state), I didn’t do damage per se, but just prevented myself from developing to my full potential? Hopefully, it’s not too late.

        Thanks again,

        • Ketorunner:

          Basically. And while lost time can’t be taken back—someone who had every advantage for all their life will be able to perform at a higher level than someone who was disadvantaged for a while—this doesn’t mean that you can’t top-10 or podium at some athletic event, provided that you act and train accordingly, or at least not compete at a very high level. For example, I can think of one semi-elite ultramarathoner (can’t remember his name) who used to be addicted to meth, and was jailed for distribution. If he went from meth addiction to ultramarathons, there’s no telling what us overreachers can do.

          While nothing in the world is certain, I’d say there’s really very few people whose genetics prevent them from running 7-minute MAF miles.

          Usually, what’s preventing them is the environmental, nutrition, or lifestyle negatives that don’t let the body grow, or stubbornness or a favorite workout which leads them to train the wrong energy system.

          Like I said, the body grows like a weed that didn’t let go of a grudge. If you let that weed grow, there’s very little indication as to where it’s going to stop, and it’s almost always far beyond what we imagined.

          • Ketorunner says:


            I really appreciate your insights and advice. And your analogies a spot on.

            I think I know the ultra marathoner you a re talking about (not personally). He is a great example. Truly amazing how he turned his life around. I think he won the Western States twice and if I’m not mistaken, his diet was a big factor (think he is fat adapted).

            I would love to run 7 minute miles at MAF. But that is going to take a while. I did a 5K last week at just over 7 minute pace but it was way above my MAF.

            Thanks and all the best!

  • George says:

    I am a fan of the Maffetone method since 2002 when I purchased the Triathlone training disk, doing only cross-trainer for aerobics (no swimming and biking component)? Unfortunately I have lost the key and can not install the software on my current computers.

    In the past 3 years I use Suunto t6c HRM and transfer my traings to Firstbeat Athlete software which also has a training coach component. This program in every training session calculates EPOC (Excess Post-Exercise Oxygen Consumption) based on the Heart Rate Variability data. Then based on ones personal data and past month of trainig suggests your next training shedule gradually increasing ones Activity Class and performance. Here comes my problem – the software suggests that from time to time I should achive EPOC levels that I can never achieve at my MAF HR of 125 bpm. I can achieve it now by e.g. going to 140 bpm for 20 min after 30 min of warming and lower HR training. Will this ruin my MAF training program? I believe 140 bpm is much lower my anaerobic treshold which should be around 160 bpm. Then, I am a mountaineer which means 7-8 hours walking, half of it at my MAF tempo, almost every day (when in mountains). On this background what can I achieve with 30-40 min training at MAF tempo in the gym?

    My current goal is to prepare my body for an upcoming in 2-3 months time surgery (removal of the thyroid gland because of large nodules) which in the 10% bad luck case can become a very difficult operation. I am not in a good shape as since end of Aprill I am suffering from Achilles Tendonitis (it seem I have genetically shorter tendon there which frequently causes me long lasting problems ). I resumed mountaineering and training in the past month largely at my MAF rate. My second MAF test was 15% better then the 1st one (because of 1 week of mountaineering after long lay-off I believe). I still make much slower progress. But now which is the better way to go – train only at MAF level or listen to the software coach which has the superior feed back data from my HRM? Having in mind my 2-3 months goal? Also, does weight training at 12-15 reps (the pulse can rise to 140 bpm for few seconds) can harm my aerobic potential development?

    Thanks in advance for comments. And congratulations for the new look of the site!

    • George:

      EPOC is an indirect measure of the amount of lactate that you have in your body: you need to keep consuming oxygen to process all that residual lactate, basically. If that’s happening, you are training at a higher level than would be suggested for health/recovery, as per the MAF heart rate. The point of training at the MAF heart rate is that you keep levels of oxygen consumption equal to the aerobic capability of the mitochondria, which is in turn equal with your ability to break down fats (lipolysis).

      This means that you guarantee 2 things: (1) developing your long-term energy system (fats from lipolysis), which in turn can fuel you throughout your day without needing to rely on sugar from energy, making sure that there is no anaerobic function, which creates acidic hydrogen ions (H+), whose accumulation and tardy removal from the body (because of failing aerobic function) is the primary damaging factor in chronic stress disorders.

      I would suggest that you train at your MAF heart rate overwhelmingly or exclusively, especially if you are trying to recover from an injury or prepare yourself for a surgery to come. (That’s what the software can’t account for). Otherwise, anaerobic training either by looking at EPOC or LT is a good idea, as long as it constitutes a small portion of your overall athletic activity (10-20%).

  • RunMAF says:

    Hi. I have been doing MAF for about 4 months. I started at 135 not adding or subtracting and have made progress. I am now 2 years into running 4 times a week and pass the add 5 beats category. Thoughts on adding 5 beats. I do a regular MAF test so will be able to assess if still making progress.

    • RunMAF:

      This is exactly when you want to add those 5 beats. Go for it!

      Nice job on being cautious, by the way. That’s the way to do it.

      • Mike Mullins says:

        Hi, firstly many thanks for past advice!
        Been following Maff for a year now. Maff tests show a 4min 40 improvement over a 3 mile test course yet st times I am still reduced to a walk to remain in zone. I have two questions really can I increase my HR zone by 5 beats yet?? And can a run one run per week at an increased pace, not stopping to walk etc or will I be undoing the past 12 months training?
        Many thanks,

        • Mike:

          You won’t be undoing it, but you’ll be slowing down your aerobic improvement. For example, my MAF runs often occur 7-10 BPM below my MAF HR. So my point here is that going conservative is almost always a far better option than aiming a little too high.

  • Darryl says:

    I’ve read a lot about the Maf HR method and have a problem with staying at or below the recommended 131HR for my age. I eat a LCHF diet and am always in a nutritional ketogenic state (average 1.8 mmol/L). What I think holds me back is that four years ago I had Mitral Valve repair surgery, which triggered atrial flutter issues, which led to three catheter ablations. Since the last ablation 3 years ago my RHR is around 70, this despite training for and running 3 full and 5 half marathons this year. My “feel like I could jog all day” HR is around 145. My brisk walk HR is roughly 130.

    So my question is, how do I adjust the Maf HR to account for my inability to get below a resting HR of 70? Maybe it’s incorrect for me to think this way but given the number of runs I’ve completed without walk breaks it seems illogical to train at 131 when that is just a brisk walk? Am I wrong?

  • Henrik says:

    I can see that weight training is anarobic. But I do crossfit with out weigts only using my own weight. Is that anarobic or can I do that during my aerobic base building?

    • Henrik:

      Weight training does not necessarily have to be anaerobic. What makes an exercise aerobic or anaerobic is whether it happens above or below the MAF heart rate.

      • Henrik says:


        I’m reading “Training for Endurance” by Dr. Philip Maffetone and on page 87 he writes: “Weight lifting is anaerobic … and later that you can’t use your heart rate to judge if your workout is anaerobic. And “The bottom line; weight lifting is anaerobic. So treat it that way in relation to your weekly schedule” So according to this you can’t use the heart rate when you are doing weight training. So I thought that it maybe are the same with crossfit even if you only use your own body as weight. You put a lot of stress to your body and it react with getting sore. So that is why I ask if it is anarobic training and should be avoided during base building.

        • Henrik:

          Apologies. I didn’t quite get what you meant by “weightlifting.” If you mean producing the low-level torque that you need for the deadlift, the squat, the snatch, and the clean, then yes, it is anaerobic. But if you’re doing calisthenics (such as say, a turkish get-up with a 10 lb kettlebell (which doesn’t require that kind of torque) then it can be aerobic, just in the same way that an aerobic run can still be aerobic with slightly heavier shoes—you’ll just do it more slowly.

  • Jonathan says:

    – I think the key is that the MAF HR is a good approximation of the aerobic threshold.

    – Blood lactate levels essentially stay at resting levels for all running done below the aerobic threshold – meaning even if you are slightly below it, your blood lactate levels are basically the same as what they are when you’re sitting there doing nothing.

    – I think the key to most optimal aerobic development is to run just below this threshold.
    – If you run above it, then your blood lactate levels will increase slightly, at which point you’re starting to work anaerobically, and the stresses can become excessive quite quickly
    – If you run too slow though, I think the stress can (in some cases) be too low, and your progress will not be as good as it can be. That’s not to say there aren’t benefits (as in a person walking several hours per week for health benefits), but I’m more thinking about avid runners/athletes. That’s where the MAF HR comes in, because, at least for me, it is just below my aerobic threshold.

    – One thing I have a problem with though, is that aerobic thresholds are different for all activities. If I CYCLE at my MAF HR, I am already accumulating small levels of lactate and it is definitely not 100% aerobic. I can feel it. I’m pretty sure for cycling for example, that heart rates are roughly 10BPM lower than they are for running, for the same intensity level…
    – IMO the MAF formula provides a good estimation, but if things still feel out, then extra adjustments/experimentations (in addition to the +/- 5 beats depending on condition) should be made accordingly.

    • Jonathan:

      You are right on all counts except two: the one about low intensity, and the one about cycling.

      Let me address the one about low intensity: You aren’t supposed to train at MAF only, all the time. You are supposed to train at it for 80% of your total volume, and train anaerobically the rest. That’s plenty of strength training and intervals. (You only train 100% MAF when you are aerobic base-building, ill, injured, overtrained, or recovering from any of the 3.

      About cycling: You’re not right but you’re not wrong on this count. (It’s complicated; let me explain):

      Anaerobic work is a local phenomenon: the energy that is being burnt in some muscle was previously stored in that same muscle. During “anaerobic exercise” such as a sprint, your “body” is only working anaerobically in the sense that all (or most) of the individual muscles are working anaerobically. But the point about it being a local phenomenon is that one muscle may be working anaerobically while another isn’t.

      (This is partly the case why, for example, someone may gets calf cramps halfway through a marathon, while their quads remain intact). Of course, that means that their quads were more powerful, but the fact that their quads were more powerful means that they could afford to be working largely aerobically, while the calves couldn’t.

      Aerobic exercise, on the other hand, is purely a systemic phenomenon. This means that you’re taking fuel from a bunch of places and burning it in a bunch of different places: fat from the gut, the glutes, the legs, and fatty tissue within all the muscles—and oxygen from the lungs—and burning it up and down the legs, back, and hips.

      In order to create this systemic phenomenon—aerobic exercise—you need a very particular activation of the nervous system, and a particular hormonal combination. If not, fat breakdown and fat transport grinds to a halt, and you force the body to rely on the anaerobic system.

      (This is why marathoners hit the wall—their fat metabolism was impaired due to too much stress: they were running the race too intensely for their body).

      Don’t worry—i’m getting to the point.

      The difference between cycling and running is that in cycling you have 5 points of support at any given time (handlebars, pedals, seat) while in running you have at most 1. This means that running places a much higher stability tax on your metabolism than biking does: a lot of muscle groups that are constantly trying to stabilize you on the run are much less active while biking.

      This means that, at the same level of metabolic exertion (read: stress), a lot of your metabolism can focus on very few muscles while biking. While running, your metabolism must spread itself out between a lot of muscles.

      This is why your AnT is lower while biking than while running: since your overall metabolic power is overwhelmingly greater than the energy production capacity of a few leg muscles, you hit the individual, local AnT of those muscles at a much lower heart rate.

      But overall, in the systemic sense, this is still an aerobic heart rate: your ability to metabolize fats remains largely intact.

      Don’t get me wrong: you’re still producing lactate and breaking those muscles down. The point is that the aerobic system compensates by transporting that lactate through the bloodstream to be processed aerobically by other muscles. While more lactate is showing up in the bloodstream, this is metabolically quite different than while running, where the muscles tend to hit their AnT much closer together on the scale of metabolic intensity.

      • Jonathan says:

        Hi Ivan,

        Thanks for the detailed explanation – very interesting! The marathon calf cramp vs powerful quad makes a lot of sense.

        I can definitely relate to the cycling explanation also. It makes sense, as the pedalling motion is a very localised movement, and the demands on the quad muscles are a lot higher than any other muscle used (and the other stabilising muscles are not used anywhere near as much as running). Come to think of it, if I cycled at my MAF HR, everything would feel aerobic, except my quads would feel like they’re working slightly harder to keep things up (no extreme lactate build up though)! I guess the local AnT of a highly trained cyclist would be more in line with the scale of metabolic intensity, though?

        As for aerobic training, personally my aerobic pace has improved from almost 9:47/mile to 8:09/mile in 3 months of training below my aerobic threshold! Since then I have naturally started adding some low anaerobic work in the form of continuous tempo (low threshold) runs. They seem to be helping my running fitness and giving a boost to my general aerobic training as well.

        Back in August my MAF pace was approximately 8:50/mile, and I did a 5km in 21:33. Interestingly, this agrees almost perfectly with the MAF tables (9:00 MAF pace = 21:45 5km). When I can do 7:30 miles aerobically then I’ll be very happy. Sub 7 miles – that’ll be an amazing day!

        This way of training has been a breath of fresh air and definitely complements a more stress-free lifestyle. A lot more pleasant overall.
        Back in March I was doing 400m repeats and a lot of other high intensity stuff (and even worse, with no aerobic base or jogging each week). I somehow ran a 5:49 mile during this time, even though my aerobic pace was probably 10-11mins/mile.
        I find it interesting that some people can sustain a good high intensity pace/effort even though their aerobic / fat burning system is weak. It’s almost as if there is a disconnect in one direction (even though they are connected and limited in the other direction). Of course, with the high intensity approach, there’s only so far you can get if your aerobic system is lacking, which I’m glad I learnt 3 months ago.

        • Jonathan:

          I’m glad to hear you’ve adopted the tenets of the MAF method. It looks like you’re well on your way to success! And you’re exactly right about the local AnT of highly developed athletes. Think of it this way, the wider your aerobic base, the more lactate you can process at any given time. So your muscles are able to process more and more lactate, meaning that it takes a lot more lactate production for lactate to start accumulating. So in an extremely literal sense, a bigger aerobic base creates a higher AnT. (And because the primary muscles being developed in biking are the big leg muscles, that’s exactly what happens to them).

          • Jonathan says:


            Thanks again. I have 2 other questions:

            1) Even though my quads might be working slightly anaerobically on a local level, should I still continue to ride at the MAF HR? For me this is 158bpm. For example, if I ride at 148bpm, is this less effective for optimal aerobic development (since systemically it isn’t as high of an aerobic stress as it could be)?

            2) Since you say that a strong aerobic system is better at compensating by transporting lactate (such as from the quads in cycling) to other parts of the body to be processed aerobically by other muscles etc., this to me implies that a stronger aerobic system can help / carry over to non-specific sports as well. Is this true?

            Personally, when I used to cycle a lot but barely ran at all, my running did not improve very much. My MAF HR cycling speed was around 14mph, running maybe 10-11min/mile.
            But now that I’ve been running consistently for 3-4 months and have improved my MAF HR pace from ~10min/mile to ~8min/mile, my MAF HR cycling speed has improved as well, even with almost no cycling! It is now around 16mph! The weird thing is that I am feeling stronger than ever on my bike, even though all of this is a result of running. Is it normal for carry over in one direction but not the other?

          • Jonathan:

            Let me answer in order.

            1) Yes and no. Usually, it’s really difficult for people whose local lactate threshold is below the MAF HR to really sustain the MAF HR for a long time. So I would just train on the bike at my muscle LT (or below the MAF HR where I feel comfortable) and then do other training (running, swimming, rowing, etc.) at the MAF HR. Growing the muscles to the right level won’t be long, so you’re really not going to be “hindering” your training very much.

            2) Yes. Specifically, what you carry over is the ability to break down, transport, and burn fats and oxygen. What you don’t carry over is the neuromotor skills that pertain to that new sport. Now think of how this applies to biking and running: the plyometric component of running (catching air with every step) is largely absent from biking. However, the same is not true in reverse: the propulsion component of biking (pushing continuously against a pedal) is a “stepping stone” skill (represented by pushing against the ground in walking), from which you develop plyometric capabilities.

            So the ways that the muscles and joints move in running isn’t just “different” from biking, it’s more complex. So, if you train that more complex skill (in neuromotor terms) first, you can expect your gains to carry over a lot faster to a less complex skill than the other way around. Ditto for soccer players who cut back and forth all day and then try to run a marathon. Even though they need to balance out their left and right sides (since they use one leg overwhelmingly more than the other), they’re going to be ready for a 10-K faster than a lot of other athletes would be.

  • Andy says:


    I’m a 12 x marathoner who averages just under 4 hrs. This summer I started the MAF method which I did for the duration of the summer with success. I’m now training for a Jan. marathon and have jumped back over to one of my regular marathon training plans (speed day, tempo day, LSR plus cross training) as I can find no MAF marathon training guide. Does such a guide exist that outlines daily/weekly time-on-feet or distances? I’m guessing that paces would be non-existent since it’s all about HR training. Or do you just recommend finishing my regular training program and jumping back on MAF post-marathon? I’m also concerned that with MAF my 4 hr marathon will turn into 5 hr which is a lot more time than I prefer to stay on my feet.

    • Andy:

      The answer would be very different for two different people. Your best guideline to figure out how much you should train (at MAF or otherwise) is how much training your body can recover and grow most effectively from. And no, there’s no MAF marathon training guide. But what I usually do for marathon training (and just about any training, as a matter of fact) is to alternate endurance and speed training in 2-week mesocycles. I choose 2 weeks because that’s how long the body can keep synthesizing proteins for a particular system.

      (The 2-week protein cycle is also why it’s so painfully obvious—to the experts—that the ergogenic drug problem in the Tour De France is far greater than the test results let on). This cycle means that the body can’t sustain that kind of use for more than 2 weeks. This is why even elite ultramarathoner Scott Jurek lost 20-odd lbs while running the length of the Appalachian Trail. The only way to stop this breakdown of the body is to change the energy system that you’ve been using (go from aerobic-anaerobic, which Jurek couldn’t do), stop exercising (which Jurek wouldn’t do) or take ergogenic drugs (which every aspiring winner of the Tour de France basically has to do).

      So, what I do for 2 weeks is to train mostly endurance: 85-90% of my volume will be at MAF, while 10-15% will be at marathon race pace (10-15 BPM above MAF). This typically means one 7-10 mile run per week. The next two weeks I train more speed:75-80% of my total training volume will be at MAF, and I’ll do interval training twice a week for 2 weeks: I’ll do 100m intervals the first day. The second, third, and 4th day, respectively, I’ll do 400m, half-mile, and mile intervals. For example, I’d do these on tuesday and friday—as evenly spaced out as possible.

      Increasing the distance from day 1 to day 4 on gives the body to make strength and power gains that are large enough to matter but small and periodic enough to be properly integrated into the endurance base (which is ultimately the engine responsible for carrying you through the marathon). In keeping with this, I recommend that you do your race pace run on the second or third day of your first endurance week. I recommend that all days begin with ~30 minutes of mobility, stability, and skill work.

      In other words, the game here isn’t “how to make gains the fastest” but rather “how to make gains that you can keep the fastest.”

  • Jonathan says:

    Another question:
    What is the reason for adding 5bpm to the 180-age HR in experienced athletes?
    Is it because as you progress, your aerobic threshold HR increases by 5bpm?
    Or is it because with my years of training you are better able to handle slightly more stress than a beginner.
    Or maybe both?


  • Mircea Andrei Ghinea says:


    you say: “starting by giving up the endless search for the magic pill, the perfect diet, or the one-size-fits-all training program.”
    my question is: isn’t the 180 Formula one-size-fits-all training program?

    just to make it clear, i really find interesting the 180 Formula and the maximum aerobic heart rate idea. looking forwards to put it in practice.


    • Mircea:

      Thanks for your comment. The 180-Formula has built-in adjustments specifically in order to adapt to peoples’ different situations. It doesn’t work for absolutely everyone (there’s people with uncommonly low maximum heart rates for whom the formula doesn’t work well, for example), but this is still a far cry from “one size fits all.”

      Furthermore, the 180-Formula is just a metric that you use to figure out someone’s MAF heart rate. The deal about MAF is that someone’s aerobic function can be impaired due to a variety of issues and illnesses. A lot of time, these issues and illnesses won’t let you progress even if you are doing “aerobic” training. So in the process of developing aerobic function (which is the foundation for all athletic gains), you need to go far and wide in search of answers that are specific to your situation, or the situation of your clients.

      What the MAF Method does is turn the focus of our efforts on the foundation of health and fitness (the aerobic system) instead of focusing on other, more superficial metrics such as power output, race time, or VO2 Max. The reason these metrics are superficial is because power output and race time only tell us how fast someone can run a race—but not whether they’ll be completely trashed afterwards. VO2 Max tells us how much oxygen the body is capable of consuming (or consuming at any given time), but again, it won’t tell us if the effort to consume that oxygen is more than the aerobic system can readily recover from.

      The point of the MAF Test is that it can tell us all these things.

  • Hi Ivan,
    I have recently seen your work and will be starting on the programme ASAP, I have been doing sandbag training for a number of years. I am 65 yrs old and in good health. I will be training at MAF rate of 120 (added 5 ). Can I utilise sandbag training provided I can keep my levels between 110 – 120. The problem is that spikes in HR can occur over the 120 mark. Is this then considered interval training even if say over 30 minutes my HR went to 130 say for a total of 2 minutes. I have just ordered your book. Thank you

    • Basil:

      Thanks for your comment. A few spikes aren’t a problem. Although for the sake of consistency and effectiveness we want to keep these spikes to a minimum, a few short periods where your heart rate accidentally spikes won’t slow down your aerobic development. The most important thing is to make a habit to keep the heart rate below MAF.

  • Henrik says:

    You write that the 180-Formula doesn’t work for absolutely everyone (there’s people with uncommonly low maximum heart rate for whom the formula doesn’t work well). Can that also be the case for someone with a very high maximum heart rate?
    I don’t know if I have a high heart rate, but just before I started training this way I ran a 5 km where my heart rate was on 180 just before the end. A week after I started this training I ran a 13.3 km in just under 1 hour (4:30 min/km) with an average heart rate at 167. I am 56 years old an therefore my MAF is 124. I haven’t run injury free, so I don’t add the extra 5 though I have been running for 30 years. I have now been training MAF at max 124 heart rate 5 days a week (total 50 km incl. warmup/off) for a month. Before I ran 6 times and 60-70 km a week. My MAF test haven’t changed I still run just above 7 min/km. So I was thinking that my MAF heart rate maybe is to low to make any progress or is it to early to say that?

    • Henrik:

      It’s too early to say, but let me expand on some of the topics you addressed.

      Having a very high maximum heart rate doesn’t change the 180-Formula. Aerobic function is a measure of the metabolism’s capability to break down fats and utilize oxygen. This means that it’s not really tied to heart function, but rather to how well your lungs function, how well you can activate your hormonal system can break down and transport fats, and how many mitochondria are available to burn fats in the presence of oxygen. You can have an extremely powerful heart that tolerates a massive heart rate, but at the same time you may be deficient in these areas.

      The reason that the converse doesn’t hold—a lower MAX heart rate in an untrained individual cannot accommodate lots of aerobic function—is because your MAX heart rate is a measure of how much stress your body can handle. You need a very specific mixture of hormones to break down and transport fats. This mixture changes once you get above a particular threshold of stress—other (stress) hormones come into play. So, if the 180-Formula predicts that your MAF heart rate is 135, but your MAX heart rate is 150, those stress hormones may start flooding your system at a lower heart rate than the 180-Formula would predict.

      BUT if your MAX heart rate is very high and your aerobic system is not very powerful, you may exceed the ability of your body to break down and transport fats, take in and transport oxygen, or burn fats in the mitochondria at a lower percentage of your MAX heart rate. In other words, if you set the 180-Formula to your MAX heart rate, you may be aiming too high.

      I hope this helps.

      • Henrik says:

        Hi Ivan

        Thanks for the answer. I have been thinking a lot about your answer and I think I understand it, but there is still a question in my mind. Why do the MAF fall with one stroke each year? My max heart rate is the same as it was 15 years ago (just above 180) and my resting heart rate also the same (just above 50). So why is it my MAF is 15 stroke lower today (MAF124) than 15 years ago (MAF139)?

        Can you also tell a little bit about how to train if you have exercise-induced asthma (no allergies). I haven’t seen anything about that. Do you do anything different? Lower MAF or??

        Thanks in advance

        • Henrik:

          You subtract 5 for asthma, respiratory illness or inconsistency in training. (I, for example, subtract 5 because I have a pretty serious muscle imbalance).

          How did you come to know your MAX HR?

          • Henrik says:

            Hi Ivan
            When you asked the question how I knew my MAX HR I thought i better check my running notes and it was wrong what I remembered. I 2002 I could remember a training with my club where we ran several intervals and were competing against each other. The last one were starting flat and ending up a long hill. I was a little tired and started slow. But half way up the hill I had found the speed again and thought I might be able to catch up with one of the others. I gave me 100% and thought I had to slow down because I was at my max. I manage to continue all the way to the top at max and there was absolutely nothing left. It was all out and my HR was 192 (just checked it) but I remembered it as 182.
            Two weeks ago I was in a race and 2/3 in the race after a long stretch with tail wind were I catched up with several other runners my HR was 179. It was not at the end of the race and it was not all out, so I thought my MAX HR would be a few stroke higher and I therefore thought I had the same MAX HR as 14 years ago. But I remembered wrong it is 10 strokes lower. Sorry for the question about the lower MAF.

          • Not at all. It’s very important for people to be inquisitive and to challenge me to produce a satisfactory explanation. This is ultimately about fostering your athletic success, not about making it easier on me.

  • Ketorunner says:

    Hello Ivan,

    I made an interesting observation the other day when I went out for a run and would like your opinion. I live in north eastern US. And as you know, it starts to get quite cold in the mornings at this time of year.
    My MAF is 129 and I have been running using the formula for about 3 months. I usually stay at 129 bpm give or take 3 or 4 beats and it has been working very well. However, when I started my run this time (very slowly to warm up), I could not get my heart rate down below 140. Sometimes it would go as high as 150.
    The only things that have changed is the cooler weather and that a few days before I did a marathon. So, do you think the weather or the race is affecting my MAF?
    Also, I’m not sure where you live and where you run, but is seems to me that unless you have ideal conditions, mostly a flat course, nice climate, low humidity, it is extremely difficult to keep a steady heart rate. What do you think?
    Looking forward to hearing from you.


    • Ketorunner:

      Definitely. Running is just like Formula I racing—everything, even whether there is a low pressure system—affects the performance of the vehicle. (Lower air pressure creates less downforce at the same speed). So the short answer is “yes, absolutely, there is definitely a “goldilocks” zone for running, where you perform better than if it is too hot or too cold.”

      What’s happening to your body specifically in colder weather is a conflict of interests: the body wants to keep the superficial blood vessels and the capillaries in the lungs constricted in order to keep blood in the core, but the need for exercise means that it has to relax those blood vessels to let blood towards the skin and limb muscles. The conflict of interest itself, more than the particular details of what the conflict is, is a stressor. So your heart rate tends to go up.

      But heart rate also tends to go up once the body is all warmed up and all those blood vessels are relaxed: you are losing heat at a faster rate so you need a higher heart rate to maintain a faster metabolism.

      The fix to this is an imperfect science: layering. The first and most important thing that my body needs to do to perform well is to allow blood to perfuse the legs—the thighs in particular. So I use warm compression tights (my personal favorites are Icebreaker, due to the merino wool) and I’ll take a very light running jacket over a tanktop—just enough to create some warm air around my upper body. As the weather gets colder, I’ll upgrade to thicker long-sleeve running shirts, and start wearing gloves.

      Generally speaking, I prefer to be a little hot to a little cold: running in cold weather without proper layers tends to be just stress, as I mentioned above. But while running in hot weather is also stress, we have a huge system dedicated to dealing with the heat: the sweating system. (We have about 5 times more sweat glands per area of skin than the next sweatiest animal: the horse). Reasonable amounts of hot-weather stress means that we are training that system, and expanding our athletic potential.

      I hope this helps.

  • Ketorunner says:


    Tremendously helpful. It makes perfect sense. I like the F1 analogy. Do you have any suggestions for warming up in cold weather? It took me almost 3 miles before I felt warm and comfortable enough to relax and enjoy the run. Running at my 129 MAF took forever to get my blood flowing to the extremities.

    Thank you.

    • Ketorunner:

      The warm-up does take longer if you do it outside. One thing you can do is wear your cold-weather clothes inside, and maybe jump rope for a few minutes. Once you feel your skin starts to get flushed, you know that blood is getting to all the appropriate corners of your body. Finishing your warm-up outside shouldn’t be a problem then.

  • Ketorunner says:

    Great! Thanks.


  • Ib Broennum says:

    Hi Ivan,
    I am a big fan of the MAF way of training and testing, and I find a lot of your answers here at website to be most informative. I have most of the books, and have found a lot of good information in them.

    As a lot of other people getting older, I have had a hard time accepting the low heart rate I have to respect and train below. I also found the normal calculation of traning heart rate to be giving me a too low heart rate to train below ( I am 56 years of age, in good shape, no medical record etc. and my body age when tested is 41) why I had a max effort bike test made measuring my breath while excersising to see my fat / carb burning.

    My problem is that the test system used to analyze the raw data, and / or the analyzer, seem to have a hard time finding my correct training zones, both for heart rate and for power.

    The problem seem to be my level of fat burning is higher than normal, as I have been fat adapted for months and eat a low carb diet. I did the test without carb loading the days before.

    It is possible to email you the raw data and the test result / zones for a quick guidance of whether I can trust the zones based on the data from the test? It would help a lot.

    BR / Ib

  • Hi Ivan,
    Thank you for your reply. I have just completed The Endurance Handbook. With regards to training I thought that anything over your MAF was anaerobic and below MAF was aerobic. Is there any difference running anaerobically (above MAF) or whether you achieve this anaerobic (above MAF) stimulus by doing say kettle bells or even a constant weight training session (maintaining above MAF for a full session )
    Finally if I did one strength anaerobic session a week of mainly kettle bells should I try and work at say MAF plus 15-20 as a rough guide.
    Thanks for your help.

    • Basil:

      The only difference is that your anaerobic gains won’t go towards benefiting your running ability (unless you do gait-related kettlebell training such as split squats, split-stance deadlift, etc).

      Your target heart rate should be tied to your training goals. If you’re trying to increase your deadlift 1RM, for example, you’ll have to let your heart rate get near maximum.

  • Nicole says:

    Hi, just discovered your website and it all makes a lot of sense.
    I plan to start MAF training as I feel I am not improving, possibly from running easy days too fast. My question is that my MAF heart rate is 120 (55 year old female getting over Achilles injury) which seems scarily slow. Where I live there are a lot of hills which are difficult to avoid and so naturally my HR spikes and then it takes several minutes to come down again unless I stop and rest a bit. What do I do in this case? Walk the hills? Rest after each hill?

  • Keating says:

    Do you have any experience integrating the MAF Method with the Jeff Galloway run-walk-run method? I have been training and racing using a 3 minute run:30 sec walk interval cycle. I have no problem running at my 180 formula pace (180 – 70 + 10) for 5 miles but I can’t imagine giving up the walk breaks without injury for longer marathon training distances. What do you recommend?

    • Keating:

      Thanks for commenting.

      Galloway is great. The important thing is that you know that you’re not overreaching, given your distance and speed of choice.

      I’d like to mention something that strikes me regarding these words: “I can’t imagine.” When you’re going to test your body in a marathon, it’s always better to know than to suppose. I suggest that you go find how long you can run at MAF before the race, or get close enough to your limit (without injury) that you know more or less how much you can travel at MAF pace safely. Who knows, you may find that the answer is “26.2 miles.”

      (For perspective, we suggest to athletes that marathon race pace be 5-15 BPM above MAF.)

      Even if the answer is that you can only run a much shorter distance, you’ll be empowered to use Galloway’s method much more tactically, and be able to tweak it to your particular needs. But until you know what those needs are, you can’t use the Galloway method to its fullest potential.

      I hope this helps.

  • Lisa Cockington says:

    Hi, I’m really trying to follow this method but having difficulty maintaining a HR measurement. I have changed to a soft strap, I’m using gel but after about 20 mins my heart rate drops from my targeted 129 to somewhere between 60 – 70 bpm. It doesn’t matter if I wet the strap sensors again – I just keep getting these low readings. And I’m definitely not fit enough for this to be real. So I work on the assumption that for some reason its only picking up every second beat and keep it under 65, or stay at the speed I was running initially. But this makes it hard to know if and when I can increase my pace, as I have no confidence in what my real HR is. Do you have any suggestions/explanations of my HR reading issues, or advice regarding knowing when to increase my pace?

    • Lisa:

      The most likely problem is that the connection fails after 20 minutes, possibly because the gel is drying. Have you tried using water instead?

      Other options: have you tried changing the battery? Also, for best results, wear the heart rate monitor centered on your chest just above the solar plexus.

      • Lisa Cockington says:

        Thanks Ivan,
        I have tried everything, water, extra gel, sweat, saliva, new batteries, different positions. Yesterday I ran for 2 hours with an average heart rate of 62 bpm. The HRM stopped working within 5 mins, and even in the first 5 mins never went above 70 bpm. If I wet it with saliva it would show a reading and disappear within about 10 secs. When I took off the HRM it was wet with sweat. But its not really the lost connection thats a problem it is the low readings which seem inaccurate. I’ve struggled with these for as long as I can remember. I see resting HR’s of 38bpm, and many times I have had continuous readings but they are all in the 60’s and 70’s, and other times – what I would consider normal (120’s – 150’s). Do you think the low readings are still a connection/transmission issue or a symptom of something else? Would it be worthwhile trying one of wrist sensor devices that are around?

        • Lisa:

          Wrist sensors are interesting, except that they are a little “noisier” than chest straps: they look at the pulse in your wrist arteries, which by virtue of being far away from your heart, already has a little turbulence in it. The pulse isn’t as clean as it would be in the neck or the temple. Also, when the muscles in the forearm clench, this often obscures the reading. (It isn’t a problem for runners, but it stops wrist and arm monitors from being truly multisport).

          I think from what you’re talking about that you have a faulty heart rate monitor. Does this always happen with heart monitors?

          One last possibility: do you have a pacemaker? It can interfere with the reading of chest-strap HRMs (which detect the heart’s electrical activity)—although the heart rate monitor CANNOT interfere with the pacemaker. In that case, an optical (wrist or armband) monitor is the best option for you.

          • Lisa Cockington says:

            I’ve had this issue with every HRM strap/device I’ve ever owned. I also am aware that I have a very strong sounding systolic output which creates a “whoosh” when listening to my HR (advice from an anaesthetist), and potentially overshadows the next beat. (and no, no pacemaker) So I wondered if the chest strap was being fooled by this, and the noise may have quietened by the time it reached my wrist.

            So of interest – I trialled a Fitbit Surge (wrist HR monitor) and I now have reliable HR readings that are consistent with my effort and activity. I’m actually thrilled because it means I can work through the MAF method appropriately, rather than guessing all the time.

            So I’m considering it a restart of my training – and can’t wait to see if I can achieve improvements.

          • Awesome! Let me know how it works!

  • Gabriel Hesson says:

    Hi Dr. Maffetone and Ivan,

    Despite sharing the usual fears that many of the athletes who have adopted your methods have had, I have decided to give your program a go for the next six months. I’ve been using the 180 formula to guide my runs for the last 2 weeks (141 bpm in my case) but have not seen any improvement in my pace so far. While it’s discouraging, I think that’s normal, right?

    My other question is about strength training. I like to do 5 – 10 different body weight and core exercises each day (i.e. squats, lunges, push-ups, planks, etc.). In the book I’m reading (The Big Book of Endurance Training and Racing from 2010), it seems pretty clear that Dr. Maffetone discourages beginners from engaging in these exercises until they have built a 3 – 6 month aerobic base. However, in some of your answers to questions in this thread, Ivan, I get the sense that you feel that this kind of light body weight training is okay. Could you offer a bit of clarity here? I’d like to maintain some more generalized athleticism over these next few months of aerobic base building, but if it’s a major hindrance, then I’m willing to let it go.

    Thanks in advance for your guidance on the 2 above issues (progress at 2 weeks and strength training),


    • Gabriel:

      You can’t expect aerobic results that quickly. They will come. Another thing to keep in

      Most light bodyweight training is overwhelmingly aerobic.

      That said, remember that you’re reading the book of Endurance Training and Racing. If you want to participate or compete in endurance sports, strength and interval training will provide very few benefits, compared to the overwhelming importance of having a good aerobic base for these kinds of sports.

      If you’re trying to train for a marathon, for example, you’re really better off training near-exclusively at MAF pace (with a few race pace runs to get to know your race speed). Since your endurance performance depends on your aerobic engine, that’s what you want to stick to.

      That said, if you’re any other kind of athlete, the reasons for developing an aerobic base are different: (1) for maintaining health, which helps you train (2) quickening recovery, and (3) absorbing the stresses of athletic training and competition. So, in that case, while you still want aerobic training to be the predominant component of your workouts, strength training (whether it’s aerobic or not) won’t be a hindrance.

      (While strength training does indeed mean that your aerobic base develops less quickly, if you’re not an endurance athlete, your performance doesn’t depend on your aerobic base—only your ability to train does. So, as long as that aerobic base is powerful enough to keep you healthy, you’re good.)

      Does this answer your question?

  • Corey says:

    I rock climb and play raquetball and basketball. Would I have to give those activities up for the first 3 months??? Can I at least keep rock climbing?? haha Thanks.

    • Corey:

      Let me give you the long answer:

      The reason we overwhelmingly tell people to cut out anaerobic training and train aerobically is because most people you encounter have generally very poor aerobic systems. To make a long story short, what the aerobic system does is absorb the stresses of life: to keep you healthy and allow some level of exercise at higher intensities.

      So, if you’re ill, injured, or overtrained, these are indicators that the aerobic system is severely impaired. This is when you want to cut out all anaerobic training. The only other instance when you need to do purely aerobic training for a long period of time is as an endurance athlete—endurance athletes don’t just use the aerobic system for staying healthy and training harder: their athletic performance directly depends on the quality of their aerobic system, when for strength and power athletes it matters to a far less degree.

      This is why endurance athletes do a period of “aerobic base building.”

      How does this relate to your situation?

      Unless you’re ill, injured, or overtrained, you don’t need to give up rock climbing at all. However, since the aerobic system is essential for health, and you need to be healthy in order to recover correctly, it is important to make sure that your aerobic system is very robust. For that reason, we generally tell athletes that 80% of their training should be aerobic, and 20% should be anaerobic (high-intensity). That aerobic:anaerobic ratio leads to a high degree of certainty that you won’t become ill, injured, or overtrained, as long as you allow sufficient recovery time and lead a reasonably low-stress lifestyle.

      While we typically recommend running below the MAF heart rate as the quintessential aerobic activity, all low-level skill and stability training, including a lot of bodyweight training, counts as aerobic exercise, when done under the MAF heart rate.

      Furthermore, any training that (1) lasts more than a minute and (2) is done under the MAF heart rate, is also aerobic. What this means is that if your rock-climbing meets these standards, you know that you are training your aerobic system.

      The same goes for basketball.

      Squash and racquetball, however, are very anaerobic sports. This doesn’t mean that you shouldn’t do them, but it does mean that they fit into that aforementioned 20% of anaerobic training.

  • Hanna says:

    Hi there, I came across your website and it seems to explain why after running for 9 months consistently, I have neither lost weight nor gotten faster. I was always running in the end of zone 2 and beginning of zone 3 (Karvonen) and it wasn’t effective since I think I wasn’t really functioning aerobically.
    I’m incorporating the MAF method now, trying to stay under a 139 heart rate which is very humiliating when running as I’m even slower than my already slow pace, albeit I’m hoping it will be effective.
    My question is if *all* running/cycling should be done in that heart rate zone, or only a certain amount or percentage of training? And also, for how long? Is there a suggested time period?

    • Hanna:

      Thank you for your comment.

      Generally we recommend that unless people are (1) ill, (2) injured, (3) overtrained, or (4) recovering from 1-3, 20% of athletic activity should be anaerobic (above the MAF HR) and the remaining 80 aerobic (at or under the MAF HR).

      When criteria 1-4 apply, we recommend that people train aerobically 100% of the time such that they have 3-6 months of aerobic progress (improvement in the MAF test). The important thing is to not only train aerobically, but to observe progress. After 3 months of aerobic progress, the aerobic base of someone who has been ill or injured may be ready to see more intense training.

      Generally speaking, I recommend that anyone who does not fit into criteria 1-4 supplement their MAF training with skill and strength/power training (including tempo runs, intervals, etc).

      Does this answer your question?

  • Ib Broennum says:

    Hi Ivan,

    The 5th of November you replied in this trail, that I could email you my test results at
    I have done that several times since then, but have not received a reply.
    Please check your mailbox or spamfilter to see if you have received my emails.
    I am writing you from my email:
    Thanks in advance. I very much like to hear from you.

    BR / Ib

  • Dana says:

    Hi Ivan,

    I’ve been fat adapted and in Ketosis for over a year now. I admit I don’t check regularly, but everytime I’ve checked I’ve been in ketosis. I ran 4 marathons and 2 half marathons in the last 6 years, the last being NY, just a month ago. I’m 46 years (almost 47). NY was the first race on my new diet and although I finished slower than I hoped with ~10 min pace, I didn’t cramp, bonk or hit the wall, which was fantastic! Since then, I decided to try the MAF method. Here are my questions:

    1. It’s quite stressful for me to try and run at 134 the entire run (checking my watch all the time), so I set up my Garmin to vibrate if I go below 130 or above 140. Is that ok?
    2. I noticed on my few runs so far that my average pace is at least 1 minute to 1:30 minutes slower and I have to almost power walk all the hills. Is that normal?
    3. I drink espresso in the morning! How long do I have to wait before I run to avoid caffeine effects on HR?
    4. Is it reasonable to assume that I would be able to hit the 9 minute (or slightly faster) pace by March/April when I’m planning on running a half?
    5. How many days/week shall I run with the MAF method? How long (time) can I go?
    6. Can I do runs without HR or would that interfere with the MAF method training?

    Thank you.

    • Dana:

      Thanks for commenting. I’ll answer your questions in order:

      1. I’d say to put your Garmin to vibrate if you go over 134 or even 132. The idea is to have a high degree of training specificity: during MAF runs (where the point is to train fat oxidation—which of course, enables ketosis) you really want to stick to it. On runs that you specifically intend to train other energy systems—more on this in a bit—it’s OK to go above.

      2. Yes, one of the things the MAF HR does is to minimize sugar utilization and maximize fat utilization. Your body will get faster and faster the more you train exclusive fat-burning.

      3. Caffeine isn’t that much of a problem, since it also increases fat oxidation. For example, you can try Phil’s Coffee as a good way to increase fat-burning before you go on MAF runs.

      4. Yes, provided you take the right steps. The big reason many people fail to progress in the MAF method is because they don’t remove lifestyle stressors: any stressor reduces aerobic function, which means that it reduces the “trainability” of the aerobic system—the more stressors, the less bang for your buck you’ll have in aerobic training. Also, consider that your body’s yearly long-term cycles means that it’s a little slower in the winter than in the summer. So your winter MAF speeds may not be representative of your speed when the spring comes. For people that are doing the right thing, 15-30 second per mile gains per month is pretty typical.

      5. It really depends on your present training volume. For example, spring-summer-fall I do 1h 30 minute MAF runs (1 hour at MAF HR plus 15+15 mins of w/u and c/d) 5 days a week (plus other training). But that’s me. The most important thing, as per answer (4) is that your MAF runs not create compounding stresses. For example, when I get back from my run, I’ll be a little tired but have a very mellow and stable energy level that easily lets me work, write, do house chores, etc. On the slightly longer term, keep an eye on your monthly MAF tests: if your speed starts to decrease or plateaus for more than 2 months, you need to scale back.

      6. This goes back to training specificity. While you can do runs without a HRM, they wouldn’t be MAF runs unless you manage to stay under the MAF HR. However, the MAF method encompasses a lot more than just aerobic base training: the idea of aerobic base training is to develop your aerobic system to a point that it (1) can meet your body’s day-to-day upkeep (repair itself and get rid of illnesses or injuries without them becoming chronic), (2) absorb the stresses of life, training, and racing, and (3) for endurance athletes, increase their race performance.

      So, for example, strength or power athletes (such as speed skaters) may be doing 75-80% purely aerobic training, and the rest is anaerobic. The important thing is for you to be able to know when you’re switching from one kind of training to the other. As long as you know when this switch is happening, you’re good.

  • Martin O'Shea says:

    I am going to try this method, I will be trying it out between now and the end of the year.Then starting Jan 1 I try a 6 months min to a year.
    My reason is this 47 soon to be 48 year old male , had c4-c5 fusion 15 months ago and just recently getting back. Old methods resulted in familiar progression of minor injuries/annoyances. This does seem really slow but given my neck , its seems logical.
    My main question has to do with software, when will there be an android platform? I currently use a polar h7 monitor with an android phone.
    If you are interested I will forward the results of my experiment.
    I don’t jog I waddle

  • Tawnya says:

    Hi there,
    I emailed you a few times when I first started MAF in early October. I have made progress with time and distance! For now, I am a short distance runner (3ish miles twice/week; 5ish miles once/week). My thought process is to make it to 10k run distance for my long runs and stay there until my aerobic base pace is around 10mm or 11 mm. 5ish miles hasn’t been hard; it just takes a long time!
    A couple of questions.
    1) My 5-mile run on 12/12 was 17:06 pace. My 5-mile run on 12/20 was 15:20 pace. The big difference? On 12/20, my HR strap conked out on me just as I was about to get started, so my run was based on the “talk” method. Since I couldn’t measure my heart rate, I figured I would just see what I could do. Comparing the two runs, I may have been a little more tired later in the day after the faster run (I really can’t remember; but I wasn’t wiped out). However, it definitely felt better while I was running because I wasn’t trying to run within my heart rate zone, as it takes effort to stay there. I just bought the Garmin 235, so I won’t have the chest strap issue again. Going forward… should I keep my pace at 15:20mm – 16:00mm and work down from there, and just make that pace’s heart rate my new training rate—even though it probably fell outside of the formula? I know I have reaped the benefits of MAF, and I don’t want to rush the process. So I would like your opinion.

    2) The better I can control my breath, I can reduce my heart rate by a good 3 – 5 beats (of course). So when it starts drifting up, I don’t slow down; I dial in on my breathing, and it drifts back down. But towards the end of all my runs, my heart rate trends and stays up, regardless of my (perceived?) effort. I’ve even slowed down a good 30 seconds/mm to keep in the zone, which makes the end of the run fairly frustrating. I think I am hitting some mental space where the excitement of being finished just naturally ups my rate, maybe? So at that point, should I try to keep it in zone or go by my effort?
    Thanks so much! I am also happy to hear other runners’ input. I have been reading though posts, and I am not finding many from people who are running in my pace or distance range. Feeling like a bit of an outlier.
    Thanks, again!

    • Tawnya:

      A lot of people are doing 17 minutes a mile. Don’t worry.

      There’s a couple of things that make staying under the MAF HR quite difficult sometimes. First, there’s what you point out—that staying under the zone takes concentration. Then, there’s also the fact that under the MAF HR means that people are often running far slower than they’re used to—so their cadence often feels awkward. (It’s easier to keep up your cadence if you’re going faster).

      It’s better to go really really easy (at or under MAF) most days. Don’t get me wrong, going over MAF a little bit like you’ve been doing won’t kill you, but it will slow down the speed at which you’re developing aerobically. My recommendation is standard: for 80% or more of your training, stay below MAF. If you succeed at staying below MAF for that 80%, there’s no reason why 1 day a week you can’t cut loose and really run the way you want to run. So that’s a way around the situation.

      Personally, I don’t compromise. Allowing myself to run below MAF when I intend to lets me do a lot of other strength and skillwork that allows me to develop at a much higher pace.

      My answer to question #2 ties into this: while excitement does “naturally” increase the heart rate, stress and excitement are chemically the same thing within the body. So, for example, when your heart races and your breathing gets short because, say, you just saw your favorite athlete or movie star on the street, your body just started burning that much more sugar, thanks to the stress hormones that just flooded your body. To take this to the extreme, a tiger chasing you also “naturally” increases the heart rate—that’s what supposed to happen.

      The best thing you can do is to try and control that mental space, particularly towards the end of a run. Don’t get me wrong—it’s not easy, and it’s never perfect. I always find myself daydreaming about racing on my MAF runs, and I find that my heart rate shoots up even 15 BPM. But then I clear my head and come back into flow.

      Effort really doesn’t mean much in terms of MAF: your effort is how much of your total muscle power you’re using, while your heart rate is how much of your metabolism you’re using. For example, you often see these very muscular guys running at a very low effort, in other words feeling very easy, but they are working at a very high heart rate and getting quickly exhausted. So the best indicator that you can work with is heart rate.

      However, what you can also do (although it’s a little less effective) is to figure out what pace is your MAF heart rate, go at that pace, and then do a MAF test after 30 days to figure out your new MAF pace.

      One of the things we’re doing is developing a MAF coaching certification. We’re figuring out what sorts of exercises would be good to do while aerobic base building, in order to quicken the process.

  • Tawnya says:

    Thank you! I’ll be adding 2 days/week (30-minute sessions) of mobility and heavy weightlifting soon. We’ll see how that complements my running. Appreciate the feedback!

  • Hari RS says:

    Hi, Can you tell if it’s ok to run two days in a row using this method? I would like to run with it as much as possible without causing any potential harm! At the moment my runs are 3 times per week, Mon, Wed, and Fri, and max HR is 148 (I am 32). The total time for each run is currently 45mins, but I plan on adding 5 mins to each run per week until I reach 90 mins per run.
    There is very little online anywhere with regard to how often this training can be done, can you provide some clear guidance?

    Also, how should the warm up be done properly? I tend to just hop on the treadmill and put it to 8mins 30secs per mile until my heart rate reaches 148, typically about 4-5 mins, and then adjust down easily as I go to keep the HR at 148, usually finishing around 10 minute mile pace by the end of the 45min session.

    Thank you for all your help and inspiration, I plan on sticking to this plan for the next 3-6 months and would really like some clarity!

    • Hari:

      Yes, it’s OK. In fact, a lot of people train 5 consecutive days and rest 2 days. The reason that there’s very little guidance is because everyone’s different: what’s OK for Meb Keflezighi (winner of the 2014 Boston Marathon) is to run 10 miles on his “off days.” That’s not OK for the rest of us.

      So the best measure you can use is your own: if your exercise starts making you stressed out (which even too much volume of aerobic exercise can do) that’s when you want to start scaling back. The reason is because stress itself—we’re talking about any kind of stress (chemical, nutritional, exercise, work, lifestyle)—reduces aerobic function. So, “feeling stressed” after a workout is surprisingly an excellent indicator that perhaps you should take a day of rest and do future workouts for less time.

      The best way to warm up is to take 15 minutes to slowly race your heart rate from 20-25 BPM below MAF up to 0-5 BPM below MAF. I usually raise my heart rate 5 BPM every 3min45sec.

      I hope this helps. If you have more specific questions about your situation, I’d love to answer them. It helps if you can include a little bit about your injury history and athletic history.

      • Hari RS says:

        That’s incredibly helpful, thank you! I felt like because of the low intensity of the plan I could do more, and im glad to see that I can.

        On athletic history, here are some pb’s all set in 2013
        Mile: 6mins 10secs
        5k: 20mins 33secs
        Half marathon 1hr 40mins 38secs
        8k XC: 34mins 55
        6k XC: 25mins 25secs.

        At the end of 2013 I had my achillies reconstructed after surgery to remove a bony prominence on my heel.
        6 weeks after surguy I had a DVT in from below my left knee into my ankle.
        I didn’t start running again until Sept 2014. Since then I have been running consistently, and raced 6k XC in 27mins 45secs 3 weeks ago.
        The plan now is to follow maffeone until perhaps July time, and train for a sub 1hr 30 half marathon in September 2016. Along the way I’d like to break 20mins in the 5k at some stage this year. (I ran 22mins 20 on a treadmill during a tempo run last month, I feel I could have gone faster).
        I am 6’3 and 210lbs right now. I was closer to 185lbs when I set my pb’s.

        I hope that’s useful!

        • Hari:

          In light of your training/racing history, your plan sounds very reasonable. What I would suggest, however, is for the first 15 minutes and last 15 minutes of your run to be a warm-up and cool-down. While for some people, the warm-up and cool-down may seem like a waste of time, they are incredibly important: the quality of the warm-up has a huge influence in the quality of the workout, and the quality of the cool-down has a huge influence on the quality of recovery.

          The best way to do a warm-up is to start 20-25 BPM below MAF, and slowly and gradually approach MAF over the course of 15 minutes. The cool-down is the opposite—ending 20-25 BPM below MAF. If you do add a warm-up and cool-down, I think that it’s prudent to start with 30 full minutes of MAF training, bookended by 15+15 of warm-up and cool-down. (For context, I do 1h30min runs, with 1h at MAF, but I started very similar to you).

          I hope this helps.

  • Henrik says:

    Hi, Why don’t it work for me or what am I doing wrong????
    I’m 56 years (55 when i started) old and have been running for 30 years. 23 marathons until 2010 where i got problem with my lower back/hip. A year ago i finally found out, that it was my piriformis/sciatica that coursed the problems. It is almost under control now and don’t bother my running today. I can feel it sometimes and that just make me change the way i am running a little bit and then it disappear again. I started my MAF running in the middle of september last year and haven’t trained any other way the last almost 4 months now except for 3 races. I came from Jack Daniels training program with about 60-70 km a week. Now I run 4-6 times a week with sessions of 45-75 min excl. 10-15 min warmup and cool down and i have stayed at or under my MAF (124 now 119 after you told me a month ago to subtract 5 for astma) all the times.
    My MAF test are getting slower so I wonder what I am doing wrong. I run 5 km at the same time of the week at the same route after eating the same breakfast. The only thing that is different is the temperature. It have fallen from 10C to 0C and my MAF times is:

    17/10/15 35:50 @126
    24/10/15 35:36 @124
    31/10/15 35:58 @124
    21/11/15 37:08 @124
    12/12/15 35:13 @123
    02/01/16 37:01 @124
    09/01/16 39:00 @123

    And the times for the 3 races:

    04/10/15 59:23 – 13.3 km – 4:28 min/km
    29/11/15 59:34 – 12.0 km – 4:58 min/km
    13/12/15 49:01 – 10.0 km – 4:54 min/km

    Could you please give me some ideas why my MAF test don’t show any improvement. The test last Saturday was cold and windy so that could explain the slower pace. But today not particularly cold and there was no wind, so that can be a bad running day, but still no improvement at all after almost 4 months. I have kept doing my test at the MAF I started with so that I can see if there is any improvement.

    Thanks in advance

    • Henrik:

      Cold stress can make your times plummet. I’d recommend that you in the winter you do your MAF tests on a treadmill, and even when you run outside, do a treadmill test every month. Even though treadmill running speed is not representative of overground running speed, you can still usefully compare improvement between treadmill tests.

      For example, cold stress usually makes me drop about 1min30sec per mile. It’s frustrating, but it doesn’t mean I’m losing fitness.

      Are you getting any foot/lower-leg problems—anything related to or aftershocks of your sciatica? (Hot-spots/shin splints)? The stress created by bad gait from muscular imbalances can often lead to big reductions in speed.

      There is another possibility: any change can bring stress. For example, let’s say I have tight shoulders, and I go to a massage therapist and get a shoulder flexibility routine. Now, my body has to cope with mobile shoulders, and my abdominal muscles (and gait in general) has to change to accommodate the new mobility. Even though this change will ultimately make me a better runner, it’s still stressful until the change “sets.”

      • Henrik says:

        Hi Ivan

        Thank you very much for your answer.

        Yes it is very frustrating when your times plummet and I thought it could be the cold. But it is also frustrating when you have been running under your MAF for nearly 4 months and nothing happens. I have been running a few times the last months on a treadmill and even there I can’t see my times getting better. I have been running on the same treadmill for 45 min (ex warmup/cool down) and it have been on the same pace, but it haven’t been a MAF test but close to.

        I gave you my race times as well because there might have been a development there, but on another 10K this Sunday I again ran slower in 49:44 – 4:58 min/km.

        Regarding my sciatica I have had problems with my heel on the opposite foot, but that is more than a year ago. But within the latest half year I have sometimes had a hot spot on my opposite shin right below the knee. But it is only for a few days then it is gone again.

        When you write about changes, I have for the last 3-4 years tried to change the way I run, som I will land more on the middle of the foot instead of the heel (chi running). During these 4 months with very slow running I have been very focused on landing and running the right way because it is so much better for my sciatica. I don’t think it as a big change because I have been trying to do so for a long time. But I have found it stressful to do it while running so slow and I haven’t felt it nice and comfortable to do so and I havent felt energetic after the run and wanting to do it again.

        Yesterday I felt so frustrated that I went back to Jack Daniels running calculator and entered my 10K time from Sunday. And it said that my easy pace should be between 6:05 and 6:27 min/km. I went for the same run as last Monday but trying to run about the 6:27. The running piece between warm up/cool down I ran in 6:35 min/km against last Mondays 7:34 min/km and my average heart rate rose from 119 to 129. I was so nice to run this way. I was totally relaxed and enjoyed it very much. The running flow and my midlle foot landing was much better and it was much easier to keep warm. After the run I was much more energetic and wanted to have another run right away. I felt it was much more right to run this way, but is it my right MAF? I’m 56 and have astma, so MAF should be 180-56-5=119, but can I add 5 for experienced runner (almost 30 year of running) and maybe 5 for age, then it could be my right MAF.

        What do you think?

        By the way when I run at heart rate 119 I have no problems breathing through my nose with my mouth closed. It get a little stressful when running at heart rate 129.

        • Henrik:

          I’d say stick to 119. This is not to say that you CANT run faster sometimes, only that you want to be conservative for your MAF HR, which is the intensity at which you’ll be running ~80-85% of your miles.

          The thing is, you really, really don’t want any anaerobic activity during the majority of your miles. Going a few beats per minute on the safe side will do much more for your progress than overshooting a few beats per minute.

          When the ease of running jumps disproportionately to the increase in heart rate, it’s a sure bet that you’re using more sugar, and you’re using less fat (which essentially means that you’re starting to increase your rate of anaerobic work). That, and the fact that it’s harder to breathe through your nose at 129 tells me that 129 exceeds your first ventilatory threshold (VT1) which is the point at which the body starts breathing harder in order to offset the first increase in anaerobic work.

          I bet that if you were to run for say, 2 hours at 119, while your speed would slow down dramatically towards the end, you wouldn’t really get that much more physically tired towards the end. However, if you ran at 129, you’d definitely feel that the tank is getting emptied towards the end of those two hours. This is because you’d be using far more sugar at 129. You can try this out. If that’s the case, then you know almost for a fact that 129 exceeds your MAF HR.

  • Louis says:

    Hi there, many thanks for this site, very useful and informative. I have a question and if possible will appreciate your view on this. I started using the MAF method and are into my 3rd month of running 4 times a week +- 30km. Keeping the HR% @ 76% which is 180 – 43 (age). In the beginning I was able to run somewhere between 6:40 – 7:00 minutes per km. I took 1 week off after 6 consecutive weeks of running. The last 2 weeks I cannot maintain the pace as before and are now averaging between 7:15 – 8:00 minutes per km. Any faster at the HR is goes to 80-85%.

    Why is it that it feels I am going backwards?



  • Rendy says:

    First of all, I am a follower of this method and have been seeing improvements. But I would also like to know your response to this research-based article basically saying that slow-twitch improvement adaptations peak at above 90% VO2 max.

    • Rendy:

      I haven’t heard that (more on this in a bit), but let’s suppose adaptations do peak at that percentage. The sympathetic exhaustion that training at 90% VO2 MAX creates is not something you want—or even can—maintain over the long-term. Supposing that you did train at 90% V02 Max for a few days, the sympathetic overactivity this would engender would basically cause your body to stop burning fats, activation of Type I muscle fibers would go down, and activation of Type II muscle fibers would go up.

      In other words, it’s like picking up speed for a running jump down the cliff of overtraining.

      All of this means that in terms of aerobic development, whether or not slow-twitch improvement peaks at 90% or 110% is an academic concern: it has no bearing on training decisions due to these other factors (endocrine, autonomic, etc.) and their effects on the body (and what the body can handle), despite what the article you linked to claims.

      The aerobic system is not just aerobic muscle fibers. The reason we at MAF talk about aerobic function and fat-burning is because of their implications in health and endurance capabilities of humans. What the “aerobic system” does is allow the body to take a near-limitless fuel (fats) and combine it with a near-limitless reactant (oxygen) in an engine that is built to keep working for a long time (Type I muscle fibers). In essence, the aerobic system does endurance because it lets the body fuel its workouts limitlessly, and it does health because it lets the body fuel its metabolism limitlessly and perform all the custodial duties it needs to in order to maintain its health.

      Unless the ability to break down and transport fats is not developed in conjunction with the ability to take in and transport oxygen, and those are not developed in conjunction with the ability of Type I fibers across the body to take in this fuel and this reactant and utilize it effectively, the aerobic system as a system won’t develop. (As energy demand rises past the onset of anaerobic activity, fat-burning decreases dramatically, because the stress hormones that increase sugar availability—adrenaline, cortisol, ghrelin, and insulin—also clamp down on fat utilization).

      Divorcing the functions of the aerobic system from one another (or worse, training one at the exclusion of the others), cannot create a better endurance athlete, and it cannot create a healthier power athlete.

      This is not to say that a modest amount of training at 90% VO2 Max isn’t helpful, for the very reasons that the article outlines. In fact, it’s an excellent idea—it will most certainly help round out your energy metabolism, and teach Type I muscle fibers how to process the anaerobic by-products of Type II fibers. But the suggestion that because of this, aerobic base training at a low intensity is moot or obsolete (with the clear, if unspoken, implication that therefore 90% VO2 Max training should replace it) is missing the point entirely, and to a dangerous degree.

    • Dante says:

      I recognize the author of that training science site. That’s that powerrunning guy that used to troll coolrunning, runningahead and letsrun telling everyone they only need to run 3 times a week to be their best. If I recall correctly, his ‘coaching’ amounted to leading recruits around in the military, and he’s never broken 4 hours in the marathon. I guess this is his latest site. Anyway, carry on.

  • Louis says:

    Many thanks for the reply. No injuries whatsoever, overweight yes!!

  • Tara says:


    I have been an off/on again excerciser for my whole life. Generally when I am exercising regularly, I am doing mostly high intensity stuff. I just came across this method today and would like to give it a try. I have been working on running a 5k. Started with small intervals and have worked up to a 28 min interval. After reading this site though I believe I am running most of that above my anaerobic threshold. I have also sporadically been doing HIIT workouts. I have been training this way for 3 months now and have made some good gains but my entire run feels pretty difficult, which makes me think I don’t have a very good aerobic base.

    I would like to give MAF a try but am unsure how much I should be doing at this point. Should I being doing 100% of my workouts below my anaerobic threshold or should I be adding in some high intensity workouts as well? I want to set a realistic time frame to complete a 5k race. My previous race time was around 38 min. How can I set realistic goals using this method?

    Thank you!

    • Tara:

      The first and most important thing that aerobic (MAF) training can do for you is safeguard your health in the face of more high-intensity training. So, while it’s very important to take a chunk of time off racing (an off-season) to work on exclusively building an aerobic base, if you have a race coming up in say, 3 months, I’d suggest tentatively that you do 90% MAF work and 10% higher-intensity work. For example, run at MAF 4 times per week, and faster than race pace once per week. If, say 45-minute MAF runs work for you, the high-intensity day should be perhaps a 15 minute run. with a substantial warm-up and cool-down.

      But the best you can do is take these basic principles and figure out how they work for you in particular. As I said at the beginning, the MAF workouts aren’t just building your endurance: they are also helping you recover and remain healthy in the face of the stress of higher-intensity training.

      • Tara says:


        I’ve been doing MAF training for a few weeks now. While I was previously running for about 28 minutes at 4.5 mph. I am now walk/running for 50 minutes at about 3.5-4.0 mph. This seems like a pretty dramatic difference. Does this mean that my entire 28 minute run was anaerobic?

        I’ve been doing two 55 min MAF workouts (including warm-up and cool-down) and one 35 min high intensity interval workout per week, but NO long runs. I figure it’s more important to build an aerobic base before trying to participate in races.

        Does this seem like a good plan? I’d like to add an additional MAF workout each week, as well.

        Thanks for your input.

        • Tara:

          Yes, it does mean that the 28-minute run had an important anaerobic component.

          It seems like quite a good plan. I’d incorporate an additional MAF workout if you can handle the volume without stress.

  • Mark says:

    Hi, My concern is how will I determine a race strategy or race pace if most of the training is done at aerobic threshold. During base training, I run at very slow speed to keep my heart rate at or below aerobic threshold (I am 47 so i run below 133). After base training for 2-3 months is intensity training with sprint intervals. If I never train at race pace how will I determine the pace for a half marathon or any other race i participate in.

    Thank you

    • Mark:

      You should certainly train at race pace once every two weeks at least (outside of base building). The MAF method is about training overwhelmingly at an aerobic heart rate, to become resilient to (10-20%) anaerobic training and produce the most positive training adaptations to it.

  • Luke says:

    I have tried a few times now to do a MAF training run but I get so frustrated. My target heart rate is 133 min and 143 max so I have loaded that into my Garmin and it will beep when I am outside of this range.

    I start running heart rate jumps from 60 to 170. Okay so maybe you need to warm up first, so I do a couple of laps and try again. Heart rate is too low 120s doing 5:40 Kms . So I up the pace by 10s per KM its now too high. 5:30 Kms , Heart is in the 150s so I slow a bit now its too low. Rinse and repeat until I get so frustrated I just want to rip the stupid chest strap off.

    Are these massive fluctuations due to having a bad aerobic base? Should I train in thé 120s until I can creep into the high 130s. I realise I am not supposed to use an average for this but maintain a strict heartrate ceiling but how can I do that when the slightest change in pace seems to either send my heart rate rocketing or plummeting.

    For background before this I was training at 8km twice a week around 40 mins and 20Km on the weekend aroung 1 hour 40 mins. No idea about heart rate.

    Thanks for any advice in advance.


    • Luke:

      Could be that you have a bad chest strap. That said, it’s really important to stay calm and cool and easygoing during MAF training—frustration and stress can send your heart rate way up (or just oscillating wildly). Generally, the better your aerobic base, the less your heart rate fluctuates. For example, the majority of a run, even with uphills and downhills, I can keep my heart rate within 5 BPM of MAF, and very rarely go over by 1 or 2 beats. For example, what I do is up my pace almost imperceptibly and that sends my heart rate up 1-2 BPM higher. Also, if my heart rate gets 5 BPM too high, I’ll lower my speed by a fraction of a shade and watch my heart rate slowly creep down in the next 20 seconds or so. I like to think of them as “course corrections” rather than speed adjustments. Also, everything plays a role: arm swing, leg movement, breathing, etc. There’s a lot of variables to play around with.

  • Mohan says:

    Hi Ivan,

    I am M41, running since the past 5 years without injury and improving steadily. My HM PB is 1:44 which is about 7:55 min/mile and my 5k pace is 7:05 min/mile.

    I was recently recommended the Maffetone method by a senior runner, and decided to do the MAF test with my MAF heart rate of 144. I was dismayed to find that my MAF pace is a lowly 11:55 min/mile.

    1. Why is the difference between my 5k pace and MAF pace so large? Is this normal?

    2. I went for a 3 hr long run with my HRM in warm weather. After w/u I started running at a slow pace of 12:00 min/mile in order to maintain my HR within at my MAF. However, cardiac drift caused my heart rate to rise steadily so that I had to resort to a walk-run soon. After 2 hrs of running I was forced to slow down to a walk in order to maintain the same HR. Should I avoid long runs altogether?

    Thanks in advance!

    • Mohan:

      1. It means you’re a bad fat-burner, essentially. As your body learns how to burn more and more fats, it can produce a very high rate of work at a much more aerobic heart rate. It’s normal, in the sense that it’s typical among runners, but that should decrease as you become more fat adapted.

      2. Not necessarily. Just keep doing what you’re doing. Perhaps you can also go on long trail hikes where your heart rate stays closer to MAF at a speed that feels more natural for you. But if you can keep the MAF HR for periods of 1 hour (given your race history it seems appropriate), you should be able to get the most out of your training.

      • Mohan says:

        Hi Ivan,

        Thanks for the reply and suggestions!

        From Part 1 of your reply, it is clear to me that I’m bad at fat burning.

        I shall follow the method and your suggestions and keep repeating the MAF test every fortnight. Hopefully my MAF test result should improve over the coming months.

        By the way, how do I objectively know that I have achieved an optimum level of fat burning? For example, could you tell me that a MAF pace within 2 min/mile of the 5k pace indicates a good fat adaptation?


        • Mohan:

          I don’t know. I can tell you when you are a good fat burner or a bad fat burner, but it’s very hard to say when you’re “good enough.” In other words, while it’s quite clear when someone is becoming better (they have a low resting heart rate and a low resting RQ) and when someone is bad (they have a high RQ and a host of negative signs and symptoms), how good is “good enough” is really an open question.

          For example, there are people who have a preponderance of fast-twitch muscle fibers (which burn sugar), but very few slow-twitch muscle fibers (which burn fats). These people aren’t unhealthy—they’re sprinters. It would take a colossal effort for say Usain Bolt or Asafa Powell to get anywhere near those 5k times. Are they bad fat-burners? Compared to, say, Scott Jurek or Kilian Jornet they are absolutely appallingly horrible at burning fats. But given their chosen career (which makes sense due to their muscle fiber distribution), they’re good enough supposing they’re actually healthy (as opposed to just appearing healthy because they’re also fit).

          If any of these guys tried to become distance runners—or god forbid, ultramarathoners—they’d have an extremely hard time being healthy.

          Does this make sense?

  • Lina says:

    Hi Ivan!

    I have written to you before but not received any response, so hoping for better luck this time.

    For many years I have been overtrained and suffered from burnout syndrome and are now trying to come back to a normal life again. I have tried to start walking, but the problem is that I have to go very slowly, with a heart rate at 82-87 for about max 15 minutes, otherwise I get sore muscles and joints. My heart rate is 117 (180 – 53-10). I´m afraid that if I am walking that slow, no results will show. I mean, that heartrate is below the heartrate I have when cooking dinner! Can i really start at such a low level och should I try to go a little bit faster (with higher heartrate) and decrease the time to 5 – 10 minutes instead? I am starting to feel desperate. I am a person who loves doing all kinds of workouts and now I can practically doing anything at all without negative side effects. I really want to recover and be able to go for a normal walk again without getting tired and/or getting pain in muscles and joints. I am willing to take responsibility for my health now. I eat healthy food and has completed the Two – Week Test with good results. Would be so grateful if you could help me. Thanks in advance!

    • Lina:

      It’s really not a question of what we want, or what we’re afraid of. The side-effects you are mentioning are the symptoms of late-stage overtraining. In this stage of OTS, fitness results aren’t what you need (not that you could get them if you tried). What happens with overtraining is that the sympathetic nervous system or SNS (which is responsible for activating the body) gets burned away by an excess of activity. Most of the negative signs and symptoms of overtraining are a result of this.

      OTS is not unlike someone whose liver gets seriously damaged in a car crash. They have to rest completely in order for their liver to regrow, and any kind of activity that causes the liver to become exerted stops it from re-growing.

      You can’t “gain fitness” in late-stage OTS. (It is not that improvements are unlikely—it’s that being in late-stage OTS is directly hostile to fitness gains). Someone in late-stage OTS needs near-complete rest in order to improve.

      I’m sorry to disappoint you if this isn’t the answer you’re looking for.

  • Jonathan says:

    I want to start making running primarily for health and as part of my lifestyle (no longer for performance benefits). What type of weekly schedule would you recommend with just MAF runs? How many runs per week, how many hours per week etc?

    I was thinking a 30minute run every other day?

    • Jonathan:

      That’s a good idea for the first couple of weeks, and then try adding one more 30 minute run the next 2 weeks (and so on). The important part is that exercise becomes invigorating but not too stressful.

  • Lina says:

    Hi again Ivan,

    and thanks a lot for super quick response. I really appreciate your honesty. 🙂

    You are completely right, it´s not a question of what I want and that´s why I needed your opinion. I dont want to do anything that harm or delay my recovery. I do whatever it takes to get on my feet again. If that means I have to be completely still – I will. I am aware that I have to continue to rest and be very, very careful about sleeping habist, diet, stressmanagemnatg etc. I actually wrote to you with Dr Phil in my mind and what he wrote about being completely exhuasted after a period av ilness, hospitalization etc and how he started to walk for about 10 minutes per day and a year later he could walk 45 – 60 minutes. I thought that maybe there was a small chance for me to start doing that now. I know that there is not one answer, but for how long can I expect to be in this state, if I do everything “right” – eat and sleep well, total restg, stressmanagement etc, approximately. Is there any chance for me to recover att all? Again, thanks a ton for your respons. I really appreciate it.

    Warm regards


    • Lina:

      Yes, within reason. You will almost certainly recover. Whether you gain back absolutely all your fitness is a matter of time, luck, and dedication. One thing I suggest is to not think of things as “training.” Your body might have a very different response, say, to a stroll through the park (I use the word “stroll” to conjure up the image of truly leisurely walking) and the kind of walk that might arise from you thinking “I’m starting to build my aerobic base again!” Also, consider taking up meditation and breathing exercises. Breathing is the cornerstone of autonomic balance, and one of the things that, for example, belly breathing does is to balance and strengthen your nervous system.

  • Craig says:

    I have recently started MAF training to build an aerobic base. I am a M49 with a 2-3 year of endurance training. I have been using a MAF HR of 134 simply using a slight adjustment up. In the past, I was definitely training in the cardiac black hole. I am struggling to maintain my MAF HR while trying to maintain a 180 cadence. My question is should I sacrifice cadence (go much lower than 180) or maintain a run/walk? By run/walk, I mean a 180 cadence when running but when I hit the MAF HR then walk until a lower threshold of of 115 is reached and then resume running with 180 cadence.

    • Craig:

      Try to keep a slightly higher cadence if possible.

      To be clear, the “cardiac black hole” refers to people doing the majority of their (slow) miles at a particular medium intensity. The fix for this is NOT in fact to run all your miles faster, but rather to run the (majority) slow miles slower than the cardiac black hole and the minority fast miles faster. If I understand you correctly, you’re training the majority of your miles above what you consider to be the cardiac black hole. If this is the same black hole that other authors describe, you may be exposing yourself to health and injury risks.

  • Lina says:

    Hi Ivan,

    Thanks for reply and advise. I have read the “The big book of health…” and “The Maffetone method..”many times the last couple of weeks and are now following every advise in the book, including respiratory biofeedback, and yes, it really helps calm down the whole system. But I wasn´t quite sure about my “walking” speed. I recently started to take a stroll, that is what I meant by start to build my aerobic base. Sorry I wasn´t clear about that. But I doubt a little bit whether that pace was perhaps a bit too slow. Now I know that I am doing right thing and that feels really good.

    Thank you,


  • David C says:

    I’m a 37 yr. old runner and working on my first week of MAF method training. Just completed a 50 miler and have a descent mileage base but a poor aerobic base. I now realize I have been training and all the wrong intensities and really excited about changing. I’ve always been a “no pain, no gain guy”. I always wear a heart rate monitor and it was my first indicator that I was overtraining which led me to this site a couple weeks ago. HR was increasing while performance was decreasing, lack of energy, soreness and poor overall performance as I compared identical efforts over the last couple of months.

    3 questions:
    1: 180-37 =143HR Should I decrease 5 because I have been noticing a decrease in performance or am I ok to use a 133-143 goal range?

    2: I always have a very large spike in HR at the beginning of every workout. I always have and it will jump into the 200’s at times, then as I hit about mile 1, the HR drops off a cliff and settles in to normal. As I’ve started, I’ve noticed it can take 20 minutes or more of basically walking, jogging, walking, jogging to get the HR to settle in and stop spiking. Will this improve over time, or should I just expect to have a really long warmup?

    3. I can currently run in the Max Aerobic HR with zero discomfort, but I am slow. (9:30 mile per minute) I would previously run most runs in the 7:00 min/mile range. One hour or so is not difficult, but I know that my aerobic system is lacking because normally a 7:00 min/ mile would be a 170 HR. If I add swimming or biking in as a 2nd workout while still in the correct Max Aerobic HR zone, will this help to speed my aerobic building or will it decrease performance because I’m not resting enough. Basically, am I going to slow my aerobic base building by trying to do too much too fast?

    Thanks so much for your help, this site and all the replies are fascinating!!!

    • David:

      1) Yes, it’s best to play conservative.

      2) It will improve, but some sort of 12-minute warm-up is just about inevitable and necessary.

      3) While more is better up to a point, it’s important to understand how much rest you need to get. So it’s better to slowly ramp up the amount of aerobic training you do.

  • MAF Enthusiast says:

    I know you have mentioned this: “the best measure of whether your training is right for your body is whether you return “stressed out” from a run (or begin a run “stressed out” the next day). If you do, you’re going too hard.” I also know you said that RPE at MAF can vary depending on how aerobically fit someone is. E.g. someone who can run 6-7 min/mile at MAF is likely to have a high RPE and breathing, especially compared to someone with a 10-11 min/mile MAF who might feel like they’re doing nothing and barely breathing.

    My question is, how, in this case, does one distinguish the difference between: (1) a slower athlete being slightly anaerobic at a lower RPE VS (2) a faster athlete being fully aerobic at a higher RPE – which could be mis-interpreted as anaerobic. (I did read that a high RPE can trigger an anerobic/stress response in the body too, but assume this is not the case.) The first athlete might feel good despite being slightly anaerobic, but the second athlete might feel slightly stressed despite being aerobic.

    Finally, on one hand I have read that the best, most aerobically-fit athletes are the ones that breathe hardest/most at the lower heart rates. But on the other hand I have read that one should be able to approximately gauge that they’re working at the correct intensity by checking their breathing. You said that max aerobic / fat max should occur closely to the point where the exhale of each breath feels slightly heavier than the inhale of each breath (relating to fats/oxygen/co2). Does this still apply to the higher breathing / fast MAF athlete, or would this athlete still have equally “weighted” exhaled breaths, despite the breathing being heavier/faster in general?

    So many questions, but since I’ve read that a lab test to determine these things would be more accurate and that the formula could be out by a few beats (which technically could be the difference between aerobic vs anaerobic training), I just wanted to make sure that I’m going at the correct intensity, so I want to cross-check my MAF HR with how it should also “feel” at the same time!

    If you could provide the key details (like the one at the very top of this comment) to gauge the correct MAF/aerobic intensity of how it should relatively “feel” and what to look for etc., that would be very useful!

    • MAF Enthusiast:

      Thanks for your e-mail. Just so you know, you’re wandering into pretty high-level territory here (to which I say “good for you”). But this does mean that you have to start considering some pretty fine distinctions, so be warned.

      This is what I’m talking about: there is a difference between “breathing harder” (a.k.a. using more of your lung capacity more quickly each breath), and “exhaling heavier” a.k.a. expelling more CO2 per molecule of oxygen than before. This “exhaling heavier” occurs at VT1. (I’ll get to RPE and stress in a second).

      A lot of the better athletes breathe harder at a MAF HR because they start exhaling heavier at a higher lung use than less trained athletes. The interplay is between the muscles’ ability to process fats (and the supply of fats) and the lungs: the more your muscles are able to use fats, the more energy you have to be requiring to turn to sugar, which in turn means that you’ll be turning towards sugar at a relatively higher rate of oxygen supply (and therefore lung use) than a less trained athlete.

      So, a more highly trained athlete will be breathing “harder” than a less trained athlete at their (much faster) MAF, but no more “heavier” than the less-trained athlete.

      Generally speaking, the best way to distinguish the difference between the less-trained athlete running anaerobically at a lower RPE and a better-trained athlete running aerobically at the higher RPE is through experience (barring, of course, the use of a heart rate monitor). In other words, what I’m talking about is accumulating a history, a personal record of what it feels to run long miles at your MAF as indicated by your heart rate monitor, and then study the gestalt experience of returning from a truly aerobic workout and how it feels afterward, and then doing the same by linking your understanding of your breathing “heaviness” to how the workout feels afterward: does the residual stress indicate that the workout was “aerobic” at that breathing type? What happens if I go just fast enough to breathe a little heavier?

      Amassing experience with asking and answering those questions is really the best way to move away from heart rate monitoring. I believe that much of what leads the best athletes to fame and glory (beyond their training and physiology) is the ability to unconsciously (and unknowingly?) ask these questions and learn to answer them effectively.

      As I said, these are quite advanced waters. But what I’m asking of you is not unlike asking the race car driver to describe the grip of the tires before they heat up as opposed to after, or whether a slightly splashy suspension is altering the car’s handling. My point is that we regular drivers rely on our car’s computer to do all those things for us. To become a competent race car driver, we have to learn that stuff. It’s the same for athletes.

      Hope this helps.

  • Lina says:

    Hi Ivan! I wrote to you about 3 weeks ago regarding my late stage OTS and a supplementary question has arisen and I would really appreciate your expertise on this. You wrote that I need near-complete rest and I wonder if you would be so kind and elaborate some moore on that. Does it means that I need total rest like almost staying in bed the whole day? Or does it mean that I can take a stroll in the park? Or should I wait to do that until I have recovered some more? I dont mind being still. I just don´t want to mess things up again. I hope you can help me to find some clarity regarding this. Thanks in advance!

    • Lina:

      It’s very hard to know what amount of rest you need, but the general, basic guideline for people in late-stage OTS is to not do anything that looks like it might be training. Some people are overtrained severely enough to warrant complete rest, but others can benefit from the stroll in the park. The quick-and-easy way to know whether the stroll in the park is what you need (barring an in-depth medical exam) is to see where there is any fatigue, tiredness, sharp increase in heart rate, low energy afterwards, etc.

      In short, if the signs and symptoms that led you to conclude you were overtrained reappear in any fashion, you need a greater measure of rest. If they don’t and the stroll in the park feels like a genuinely restorative experience, you know you’re on the right track. So if you take one stroll and see those signs and symptoms peek out again, rest. If you listen to the symptoms and respond accordingly, that learning experience will help accelerate recovery.

      I always like to think about exercise and recovery in this way: if my body was trying to speak to me in this very instant, and I was forced to come up with an interpretation, what would my body be saying?

  • Lina says:

    Thanks for coming back to me!

    I kind of already knew the answer. 😉 It is common sense – listen to your own body! Easier said than done but oh so true. My problem is – as you can tell – that I dont trust my own instincts. But fortunately for me, I have at least an ablity to recognize a wise person when I met someone. 🙂

    I checked out your blog and read about you here on Maffs website and have to say that I am very impressed by your journey. What a perseverance and determination you show. I will have that in mind on my own way to recovery. You story is very inspiring. Thank you!

    • Lina:

      You’re welcome, and I’m glad my story could help you! What has helped me in the past is to cultivate a sense of pride over making the difficult choice. As long as that choice is well-informed and well executed, it does pay out in the long run!

      Remember, don’t fall into a rut, either in recovery or training. Keep testing new things, keep asking new questions, and keep inventing your way to recovery and better health and fitness.

  • Lina says:

    Hi Ivan!

    Thanks again for your advice. 🙂

    I have been following yours (and Maff´s) advice now for a month and the muscle soreness is already almost completely gone, and so is the plantar fasciitis. 🙂

    I have reduced my omega 6 and increased omega 3; eliminated almost all sugar and are eating more fat and protein. I am doing the biofeedback breathing exercise 3 – 5 times/day and meditating 2 times/ day at least for a minimum of 20 minutes. I work hard to correct my bad posture, both while sitting and standing.

    I have made a “stresslist” and are eliminating them one by one and it feels great, very empowering, and I am already very proud of myself for coming this far. I do absolute nothing that race my HR. I´m actually spending most of my time sitting or laying in bed. And I have to say that I find it very satiesfying – I need do nothing and the world keeps spinning. And from that I am learning that I do not need to be perfect. (It is a privilege to have all the resources necessary to facilitate my recovery.) All of this happened when I finally came to acknowledge that I am powerless over my behavior. I have observed my behavior for so long but not being able to do anything about it but thinking …tomorrow… just like an addict. So when I finally admitted my powerlessness, it was, and is, easy to do all the right things. Sorry for rambling. 😉 This really works!


  • Cat says:

    Hi Ivan

    Firstly – thank you to your dedication and patience to answering questions!

    I have been training predominantly MAF for two months now but have seen no improvement (or even regression) in my tests. I would say around 90% of my exercise has been at or under my MAF HR and on average I am doing 10-12 hrs per week

    I understand patience is required with this method, but I am just wanting to understand when most people start to see improvement (i.e. how long should I stick with this before I give up!)

    Also – is there anyone who MAF hasn’t worked for (when done properly/consistently)



    • Cat:

      Usually, MAF training should start kicking in within 90 days. When it doesn’t immediately start producing speed, it’s because it’s clearing up symptoms of bad health (and then, once reasonably full health is achieved, your speed increases begin to kick in).

      The usual explanation for MAF not working for someone is that they confuse—not unreasonably—“doing aerobic training” with “promoting aerobic function.” Of course, doing aerobic training is the quintessential way of promoting aerobic function.

      When the body is besieged by stressors (bad nutrition, bad sleep, work stress, constant uncertainty, travel, chemical stress), all those put a dampener on aerobic function. So what happens is that people go out to run MAF—“doing aerobic training”—while their aerobic systems are still incredibly suppressed by all these different stressors. So, doing training that should theoretically be aerobic doesn’t really produce a lot of bang for your buck.

      You’ll get more bang for your buck for your aerobic, under-MAF training, to the degree that you’ve removed stressors from your psychological and physical environment. The inconsistencies and difficulties with aerobic training aren’t due to the fact that MAF doesn’t work for some but works for others, but rather that stressors arrive in peoples’ lives at odd moments, or they don’t know (granted—perhaps because we haven’t communicated properly) that the removal of stressors is just that important.

      Please, if anyone has had a bad experience with MAF, feel free to comment.

  • Augusto says:

    Hi Ivan,

    Reading several articles in this site I can see that typical recommendation is 5 days of training, all at MAF to build aerobic baseline and a 80-20 aerobic/anaerobic ratio for a couple of months then return to baseline building, and “slow weights” strength training 3 times a week, but I am a father of 2 and I can only do 1hr early mornings, so those type of schedules are impossible for me.

    I know you are against prescribing a schedule without an individual assessment, but what would you recommend for a healthy person who has no intention of racing but just want a healthy and rounded workout routine and only has 1hr to workout per day?


    • Augusto:

      For 1 week, run 5 days a week at MAF, and the next week run 3 days a week at MAF and do 2 days of weights OR high-intensity running. 1 and 1 works too.

      • Augusto says:

        Thanks, I’ll try that. But wouldn’t “slow weights” be considered aerobic?

        • Augusto:

          No. Slow weights is a good way to do anaerobic training without it getting too much in the way of your aerobic development, but it is anaerobic. The kind of “weight” training that you can do completely aerobically is high-rep, low-weight sets of any exercise where multiple sets of 15-25 reps don’t really take you above your MAF HR (after you’re fully warmed up). Bodyweight circuit training (20-30 minutes) where your heart rate does not climb above MAF.

  • Joe says:

    I am preparing for my first full marathon and have a question. While I’m training for the marathon I want to take advantage of this time frame to shed my body fat by incorporating weight training as well. for instance I would do weight training one day and run on the next. Is this a recommended and/or effective method to achieve both goals?

    Thank you in advance for any recommendation you may or may not have.

    • Joe:

      Weight training isn’t the best thing you want to use to cut down on weight for a marathon. You’ll put on muscle mass that you’ll have to carry throughout. The best way to lose weight for a marathon is to dial in your eating (not too little, not too much, few carbs) and progressively increase the amount of aerobic training that you do. It’s fine to do weight-training say, once a week, but it shouldn’t be what you rely on for marathon-specific fat loss.

  • Joe says:

    I just recently started using the MAF method along with a heart rate monitor. As expected it feels very slow. And I know that Dr. Maffetone insists that in time I will be able to run at a faster pace at the same maximum aerobic heart rate. But is it not also possible to run at a comfortable pace even though it’s higher than my maximum aerobic heart rate? Thanks in advance.

    • Joe:

      It’s unsustainable as a habitual pace, but it’s certainly possible. In other words, choosing a higher pace for a habitual cruising pace is typically what (a) slows down further aerobic development, and (b) increases the incidence of illness and injury.

  • Murraigh McDonald says:

    Hi Ivan,

    I realise you are very busy as an editor on the website, so I appreciate your advice and time.

    I’m a 41 year old endurance enthusiast with a couple of years solid training behind me. I did a 4:08 marathon in 2015, have since got close to a 20 minute 5k and completed three triathlons this year. I now want to become an ultra-marathoner, with a 50 miler planned for April 2017.

    I was led to the MAF Method by nutritional curiosity. I really struggled through my marathon with terrible stomach ache from so called “Sports Nutrition”. I followed the advice of the manufacturers of these despicable products, attempting to consume up to maltodextrin-based 3 gels per hour! In hindsight I came to learn this was fundamentally wrong. I improved my diet and nutrition strategy for triathlon training and racing this year and feel 1000 times better for it.

    But…. my training did involve some regular anaerobic work. Concerned that I was tapping too much into my onboard carb stores, I felt I should try the MAF Method to improve my aerobic base. In my new ultra journey, I want to be able to go very long distances by fat-burning and minimal on-the-go nutrition.

    My experience so far has been similar to other people. I’ve gone from happily cruising at sub 8 minute miles to jogging along at 10 minute miles. This is frustrating, but I can live with for anticipated the long term gains.

    So far I have seen no improvement at all in my basic pace. I track everything on Strava and 7 weeks in I’m still running at the same performance as when I began. I sleep okay, show no signs of overtraining, and although under a fair amount of stress, seem to cope generally well. I’m wondering whether I’ve actually got close to my optimal aerobic pace already? Well I’ll stick at it because I love running 15 miles and not feeling stiff and sore the next day. But I was hoping to see some improved pace by now.
    Also, after about 15 miles it’s almost impossible to run. I have to jog/walk to keep my heart rate below 139 bpm. I hope that as my endurance and fat-burning ability improves, this distance increases.

    Here are my questions:

    1. I have 2 marathons in 2 days coming up (New Years Eve/New Years Day). I predict that I will have to jog/walk the last 10 miles or so keep sub-MAF. If I do run to the end and breach 139bpm, will this be overly detrimental to my base-building?

    2. Inevitably, I will need to eat on my longer training runs and ultra events. What do you recommend for this? What quantity and make-up of macro nutrients is best for digestion and energy delivery and what is the rationale?

    I hope everyone is enjoying their MAF journey, I’m convinced it’s the best way to handle a life of endurance!

    Many thanks, Murraigh (Liverpool UK)

    • Murraigh:

      Thanks for your comment. Let me answer in sequence.

      1) Races always, always carve into your aerobic base. That’s the nature of races: this is where you commit your entire physiology to get as much performance out of your body as possible. That said, building an aerobic base is so that you can race. (Also, so that you can handle different “races” in life—stressful situations, etc.)

      2) In ultra events, I like to eat a wide variety of things. Usually, it’s things that are relatively easily digestible. My go-to race fuel is a drink that’s about 60-30-10 Fats-carbs-protein (I wrote about it on my personal blog). I like that ratio because it fuels me how I need to keeps my digestion going and makes it easier for me to pace the race overall. However, lately I’ve taken to eating lots of different things. Lots of single-serving stuff: lightly-sweetened nut butters, cheese sticks. Also, sweet sticky rice desserts.

      The most important thing to consider is the hormonal interactions inside the body that produce fat-burning. If you eat too many carbs before the race, your body will increase insulin production and end up stopping fat-burning. So the most important guideline for race nutrition is to start eating anything significantly glycemic only 30-40 minutes after the onset of exercise. Other than that, it’s important to facilitate digestion throughout the entire race—eat nothing too heavy, but also enough of all 3 macronutrients that your digestion doesn’t shut down. While I’ve found this recipe to be a good template for people, actual best practices for individuals vary wildly. Generally speaking, however, most individuals do well ingesting about 150-350 calories per hour on long races. I myself consume about 300 calories per hour (at 158 lb).

  • Dave. says:

    Hi Phil/moderators,

    Got a question, is there any minimum effective dose for time of running? I mean does it have to be for a minimum of 10 minutes or 30 minutes? 1 hour? Of running. I have noticed the book doesn’t mention anything about times other than the actual MAF test. Currently I am running for less than 20 minutes, I am seeing improvements. However I am wondering is there a specific amount of time I should be aiming for to see better improvements.

    Much appreciated.


    • Dave:

      The effective running dose is specific to you. This means:

      Slightly more than your body has become used to, but still within your comfort zone. If you are seeing improvements with 20 minutes, then you are within your range of improvement. Depending on how easy this is for you, it may or may not be reasonable to increase say, 5 minutes.

      For example, my minimum running dose is 60 minutes, but my maximum running dose may be far below say, an elite marathoner’s minimum.

  • Camm says:

    I am a male 46 years old and trying very hard to stick to a MAF HR. I started MAF training back in the spring at a MAF HR of 129 (subtracted 5 for deteriorating race performance). I have trained in the “black hole” previously. Since late summer / early fall I added back the 5 BPM to a max MAF HR of 134 and have done well over 90% of running / riding at or under this HR. My progress is incredibly slow — glacially slow. I have made progress, but not significant progress.
    I went for some testing at a local university, but they didn’t have a Fat Max test. The following are my results:
    VO2 Max 51.3
    Max HR – 195
    Lactate Threshold:
    100 Watts with 1.4 mMol lactate at 119 bpm
    125 Watts with 1.4 mMol lactate at 129 bpm
    150 Watts with 2.9 mMol lactate at 145 bpm
    175 Watts with 2.9mMol lactate at 157 bpm
    200 Watts with 3.9 mMol lactate at 166 bpm
    225 Watts with 5.7 mMol lactate at 170 bpm
    250 Watts with 9.9 mMol lactate at 186 bpm

    From this, what HR should my MAF run/rides be at or under? Is it time to add some intensity? If I can add intensity — any suggestions are how best to do that.

    • Camm:

      Thanks for your comment.

      It’s most likely that your MAF HR is somewhere around 129 BPM, or at least at a higher heart rate before your lactate levels increase above 1.4 mMol. The MAF HR corresponds with the aerobic threshold, which is known as OBLA (Onset of Blood Lactate Accumulation). Since lactate production inhibits fat oxidation, FAT MAX always co-occurs with OBLA: it’s essentially impossible for rates of fat oxidation to continue increasing after OBLA. So the 2.9 mMols of lactate at 145 BPM tell me that you’ve well exceeded your MAF HR by that point.

      Adding intensity is not a matter of making your overall training HR higher (which is a very bad idea), but rather adding some training far above the MAF HR. Typically, the best point to do this is when your MAF speed has increased over a minute per mile, and has begun to plateau. So it’s very rare that someone who hasn’t seen much of an increase in MAF speed would see a MAF speed benefit by increasing non-MAF training.

      Your MAF HR is, to me, plainly at 129 BPM (or close enough to it), so all your aerobic training should occur at around that HR. However, I wouldn’t add high intensity until you’ve seen a significant increase in your MAF speed. What are the reasons your MAF speed hasn’t increased much? The most likely culprit is due to external stresses, such as nutritional stress (too many carbohydrates or processed foods in the diet), chemical stresses (from household cleaners, including dish soap), and lifestyle stresses (poor sleep, too much work stress, etc). Effectively, every single one of these stresses—and any and all other stresses—cause the body to respond a little bit like high-intensity training, inhibiting aerobic function. So, the best way to get the most bang out of your buck for aerobic training is to reduce all those environmental stresses as much as you can.

      • Camm says:


        Thank you for the feedback. So my MAF HR is effectively at 180 minus my age and an additional 5 bpm (as if injured or taking medication)? That’s pretty darn close to walking speed, but I will give it a go. I started at 129 this past March/April when I noticed a decrease in performance after a banner prior year with excellent performance.

        After about 16 to 17 weeks of training at or below 129, I moved up to 134 which is 180 minus age for me. I have also dropped the use of orthodics and adopted a primal diet (back in February / March of this year). My diet is mostly void processed foods and carbohydrates outside of veggies and occasional fruits. My work stress is certainly a culprit — started a new business in September, but work stress really broke through with a corp. transaction at my old employer earlier this year. I have successfully transitioned away from orthodics while running altogether.

        Why is my MAF HR lower than standard (180-age+5)? Is it attributed to stress?

        What kind of MAF HR speed improvements would be an indication that I should consider adding intensity (10% to 20% of total training volume)?

        My MAF HR run times are certainly better than they were when I began, but no where near a level where I could run with others? Is there a min. improved mile time that would indicate enough improvement to move forward.

        • Camm:

          To be honest, I’m not sure what the lactate change between 129 BPM and 145 BPM is. So, your MAF HR is the point where lactate starts to rise past 1.4. Based on the data we have, it’s best to assume that is 129 BPM. But it may or may not be 134 BPM, for example. We just don’t have the data to make that conclusion.

          People’s physiological MAF HR follows a normal curve, meaning that most people’s MAF HR occurs very close to where the 180-Formula predicts it does. But in reality, some people’s physiological MAF HR diverges either above or below what the 180-Formula predicts. The best way to get at your real physiological MAF HR is the way you did: with laboratory tests of various kinds.

          So it’s not necessarily the case that your MAF HR is lower because of stress. It may be the case that it just is that way. What is certain, however, is that if there are major stressors in your life, and you remove them, you will certainly become much faster at your MAF HR, or indeed, at any aerobic heart rate. However, the slow rate of increase in speed tells me that you are either overtrained and slowly recovering from it, or there are still major stressors to remove, or a combination of both.

          Generally speaking, you can expect a minute of improvement (per mile) within 12 months. And to be perfectly clear, “moving forward” with anaerobic training will NOT significantly develop your aerobic system or improve your MAF speed generously. It may open up space for aerobic improvement with further MAF training, but that will only happen if you’ve already been getting very fast at MAF, to the point that you feel like you’ve begun to exert yourself at your MAF HR. Right now, all the evidence suggests that your aerobic base is at a similar starting point to a plurality of westernized individuals (myself included), and that you can develop quite a bit at an exclusively aerobic intensity before needing to incorporate strength training to develop further.

          • Camm says:


            Thank you — that is very helpful and much more understandable. One of the issues is having realistic expectations and until now I had no way of knowing what improvement was reasonable. I definitely have a long way to go (do to stressors but more likely years and years of overtraining in the “black hole”) since I am not even breathing hard at MAF HR runs and the pace is terribly slow.
            My first mile at MAF well over a minute faster than when I started in April this year and my average over a 5 to 8 mile session is about 1 minute per mile faster.
            I guess my expectations were exaggerated.
            Will have I have to avoid races in the coming Spring and Summer until my MAF has significantly improved to the point my MAF HR runs are faster and breathing hard?

            Thank you again for helping clear some really murky water. Are there any plans to launch the App?

          • Camm:

            It’s now in the app store!

            Look for “MAF App”

  • Camm says:

    I downloaded and registered on the MAF App today. Can I load workouts from my Training Peaks or Garmin into the app or just manually key the information? My Garmin chest-strap is not Bluetooth compatible. I don’t really prefer to take my phone with me on runs anyway.

    Additionally, I have been logging workouts in Garmin and Training Peaks for approximately 9 months at MAF HR and while still very slow — I am approximately 90 seconds per mile faster than when I started. How do I incorporate this into the app?

    Why are there “YES FOODS” that include Corn (bread / tortillas), Peanut Butter? It was my understanding that one should avoid corn meal products as well as all kinds or peanut products.

    I have been maintaining a diet that favors protein, fat, and vegetables with some fruit (primarily berries) so as to maintain a fairly low total carbohydrate intake generally. Is that too restrictive?

    • Camm:

      There are two different lists of foods in the app, one for people actively doing the Two-Week Test and one for those who are NOT, who still want to keep a healthy lifestyle. Corn and peanuts should NOT be eaten during the Two-Week Test (and the Two-Week Test list does reflect that) but they may be components of a healthy, non-ketogenic diet (and the “normal diet” list reflects that too).

  • Bob Gurnham says:

    I am a 65 year old retiree who is just completing the 2 week test coupled with the MAF workouts on a daily basis. Previously I had been in the no pain , no gain world with a lot of interval training. i have completed a number of marathons and halfs and triathlons but I now believe my training methods have been wrong after 30 years. I believe my introduction to MAF (through reading Natural Born Heroes) will be transformational for me as I begin the changes in both my workout and diet routines. I find your website to be an excellent source of information and just want to say thank you!!

    I did want to ask about what is the minimum heart rate that is required to,in effect, be in an aerobic workout? In addition to workouts I do a lot of walking/hiking and I curious to know if I am in effect completing an aerobic workout?

    Thanks in advance and keep up your excellent work!


    • Bob:

      Anything below the aerobic threshold (MAF HR) is aerobic. If you stay around 5-10 BPM below the MAF HR, you are getting an excellent, and very powerful aerobic workout. That said, walking, which for most people occurs much further below the MAF HR, is also a great aerobic workout. It helps the body grow in different ways. When you get down to the details of how to have the healthiest physiology, a spectrum of aerobic activity, where you habitually hit all the aerobic heart rates, is the best way to go.

      Generally, if you walk and hike a lot, you are doing quality aerobic base training. In fact, one of the easiest (and possibly most effective) ways of developing a pre-season aerobic base for recreational athletes is by doing a few weeks of high-mileage backpacking. It’s very easy to do, you don’t really need to keep track of your heart rate, and you’re almost certain to get the results you need.

  • Steve Lake says:


    I’m 6’7″ and weigh 220lb. with a resting heart rate of 55 bpm and a max heart rate of 205 bpm. I am 41 years old. Will this same 180 formula still apply with a max heart rate that is so high? I’m afraid I will not see the full benefit on the 180 formula.



    • Steve:

      It’s not always clear. People with very high or very low MAX HR are often outliers to the formula.

      What I’d recommend is to get lab tested for the heart rate that corresponds to your maximum rate of fat-burning (FAT MAX). This point is often a few BPM below other metrics such as LT1 and VT1. If the lab can only get your LT1 or VT1, I would subtract from those 5 BPM and call that your MAF HR.

      • Camm says:

        What is LT1? How does it correspond to lactate threshold values? I too have a high Max HR value of 196 as tested in a lab and have often wondered if the MAF HR for me might be slightly higher than the 180 formula.

        I have done several MAF Test with some progress – though quite slow over the past 12 months. I have notice very very little drop off in pace during a MAF test at the same heart rate – even at the 5+ mile mark. That would seem to indicate good aerobic function, but training at 135 MAF HR is producing glacial improvements.

        Thank you in advance for any input or guidance.

        • Camm:

          Typically, when lab technicians talk about a “lactate threshold”, they are talking about the LT2. The LT1 is the point where resting lactate values begin to change. The LT2 is the one that is usually known as the lactate/anaerobic threshold.

          Keep in mind that the aerobic system is a very long-term energy system that requires a phenomenal amount of infrastructural development to really “take:” increases in mitochondria across the muscles, increases in leptin receptors across the body’s fat cells, massive development in capillary networks in the muscles as well as lung alveoli, coordination of the lymphatic system with the circulatory system, etc. By comparison, developing classical muscle power is a very simple proposition: first you increase neurological output to the muscles (from Type II motoneurons) and then you increase size of Type II muscle fibers. So developing aerobic power occurs over a much longer term because in every way that matters, it is a long-term investment, requiring the development and coordination of a multiplicity of systems.

  • Thomas Hoffman says:

    Hello, I’m currently unable to run due to a hamstring injury, but I am able to walk w/out any pain or discomfort. Should I strive to obtain the same MAF HR while walking as I would running? I am able to do this if I walk on my TM and I wear a weighted vest, and adjust the speed and incline until my HR reaches the MAF HR level.

    The main reason I ask is because walking at MAF HR sure feels a lot harder than running at MAF HR.

  • G says:

    Hi, I have a question regarding my heart rate zone. I am a very athletic 22 yo who wants to start training according to your method. My HR zone is up to 158, however I don’t particularly feel that it is an “easy” pace to hold. I did 1mile at threshold and my pace was 4.10 min/km. Do you think I should stick to it or drop my HR down?

    Thanks in advance

    • G:

      Best to start by dropping your heart rate down. This doesn’t mean that your MAF HR is necessarily lower—just that your muscles, tendons, etc. aren’t used to going at that speed for that long. Whether a pace is “easy” or “hard” isn’t a good measure of whether you’ve exceeded your MAF: as you become fitter, you’ll run faster at your MAF and it’ll feel harder—not because you’re working anaerobically but because there’s just more force going through your body.

  • Janice says:

    Hi there,

    Thanks so much for an awesome website – and all the great info! I’m super encouraged reading all the comments AND seeing that they’re getting really comprehensive/helpful answers 🙂 I’m really hoping that mine might get an answer as well as I kinda feel like I’m dashing around in the dark in some respects! (that is, been ‘studying’ this method for quite some time now… but, well, before waffling on anymore let me just get to it! I have done a few Ironman races, as well as half distances and a couple marathons and half-marathons… but, I’ve never ‘raced’. I would truly like to do great things next year and am committed to training using this method/nutrition etc. However, even after having been able to do all these races – I am finding my max HR a little silly – that is, I don’t doubt this method for a second, but I’m wondering if there’s something wrong with me! I am battling to keep my HR under 147 (I’ve used the 180-age+5 as I have been poorly/inactive for about 6 weeks now… just after my last IM race on Sept 23 of this year). So, my question is – is this normal? I went to the track earlier this week to do a bench mark test, and had to walk a LOT… and I mean a LOT 🙂 My HR averaged at 147, but had peaks of 158 etc – is this normal? And, I realise this a bit of a ‘shot in dark’ question – but, I have a marathon at the beginning of Dec – would I see any significant gains by then? (or do I brace myself for walking most of it?) And then last question – are there any ‘MAF method’ coaches out there? I’d really love some guidance/confirmation of what I’m doing is correct!

    Thanks again – really hope you made it this far and didn’t fall asleep whilst I was trying to get to my point 😉

    • Janice:

      Thanks for your comment. Unfortunately it’s very typical for people to be very slow at their MAF HR. The peaks are also common—as you train, they’ll go away as your heart rate “couples” with your effort level.

      You might see improvement. Someone who lives a low-stress lifestyle, eats well, sleeps well, etc. can reasonably see improvements of around 10 seconds per mile every month, for about 6-9 months.

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