NEW STUDY SAYS THAT WOMEN’S MAX HEART-RATE IS LOWER THAN MEN’S

By April 30, 2015 May 12th, 2015 Exercise

A recent issue of the medical journal Circulation published an important study by Dr. Martha Gulati and her colleagues from Northwestern University. They measured heart rate responses to exercise stress tests in over 5,437 women (average age 52). After a 16-year follow up (in which 549 women – a very high and alarming 10 percent – died of various causes), the researchers found an important association between the maximum exercise heart rates and age, and they determined a better max heart-rate formula for women undergoing stress tests to help predict those at higher health risk.

But the media, as is often the case with newly published medical studies, have leaped to a number of misleading conclusions. Foremost is this: Women who exercise now have a new max heart-rate formula. But the formula determined by this study does not definitively show a woman’s maximum heart rate; it’s only an estimate. The study also does not replace the old 220-formula, since this formula has been shown to be inaccurate in determining maximum heart rate in both men and women. Finally, the Northwestern study and the formula do not provide any new information about the best exercise heart rate for woman.

While the study was important because it provides more information on women and heart disease, the subjects of this study were not necessarily athletes. In fact, most were overweight and overfat, and many had high cholesterol and blood pressure, and were smokers.

The “new female” formula–206 minus 88 percent of age – provides only a general estimate of the peak heart rate a healthy woman should attain during exercise stress tests, and not during regular exercise. The study does not compare or highlight other factors that may be as or more useful in determining increased risk of heart disease, including waist circumference, blood pressure and family/personal health history, and heart-rate variability (read my article on this important topichere).

When it comes to exercise, like everything else, individuality is most important in women and men. If your goal is to burn more body fat, get thinner and more healthy or train to run a 10K or marathon (or even if you’re a professional endurance athlete), this new formula won’t help, unless you’re going in for a stress test.

Let’s look at both maximum and exercise heart rate numbers, and ways to determine them for your particular needs. The following section is taken from my new book, “The Big Book of Endurance Training and Racing,” which will be in stores by September.

Exercise Heart Rate

There are two main formulas that are associated with endurance exercise, the type most people perform. These include the 180-Formula, which I developed in the early 1980s, and the traditional 220-Formula which is older and used much less today.

220-Formula

Using the traditional 220-formula, an individual would determine the training heart rate by two steps:
• The first is subtracting their age from 220 to get their maximum heart rate. In reality, most athletes who obtain their maximum heart rate by pushing themselves to exhaustion will find it is probably not 220 minus their age. About a third will find their maximum is above this heart rate, a third will be below, and only a third may be close to what they’ve calculated. These inaccuracies are often significant.
• The second step uses this so-called maximum heart rate, which is then multiplied by 65, 70, 75, 80, or 85 percent. The percentage most athletes choose is the higher option since most feel the need to train with more intensity to obtain benefits. This results in a relatively high training heart rate. Moreover, the range between 65 and 85 percent is so wide that most athletes who work out without thought of heart rate or intensity will fall into this range.

Since everyone is unique, the 220 Formula is not accurate as it relies on an estimated maximum heart rate, which is not very accurate and a wide range of workout intensities. In addition, this formula fails to take fitness, health, and aging into account.

What is Age?

There are two ways to define age. Chronological age is measured by calendar years, but this may not be a good reflection of fitness and health. We all know athletes who appear much younger—or older—than their chronological age. Some maintain better levels of physical, chemical, and mental function throughout life, reflecting a truer physiological age, while others who are the same chronological age do not. We can evaluate these differences by measuring heart and muscle function, blood sugar, and hormone levels, and by performing other clinical tests. An appropriate questionnaire that asks about fitness and health history is also very useful to assess physiological age, and would better represent “age” in a more accurate calculation, such as the 180-Formula.

180-Formula

This approach is more individual since it incorporates the person’s level of fitness and health, and it does not consider maximum heart rate. The 180-Formula provides two important benefits. First, it trains your body to burn more stored fat for energy (we normally burn varying amounts of both sugar and fat). This is important for overall health. Second, it enables you to run, bike or perform other activities faster over time (weeks and months), all while remaining at the same training heart rate. This is important if you’re a competitive athlete.

To find your maximum aerobic training heart rate, there are two important steps. First, subtract your age from 180. Next, find the best category for your present state of fitness and health, and make the appropriate adjustments:

1. Subtract your age from 180.
2. Modify this number by selecting among the following categories the one that best matches your fitness and health profile:
a. If you have or are recovering from a major illness (heart disease, any operation or hospital stay, etc.) or are on any regular medication, subtract an additional 10.
b. If you are injured, have regressed in training or competition, get more than two colds or bouts of flu per year, have allergies or asthma, or if you have been inconsistent or are just getting back into training, subtract an additional 5.
c. If you have been training consistently (at least four times weekly) for up to two years without any of the problems just mentioned, keep the number (180–age) the same.
d. If you have been training for more than two years without any of the problems listed above, and have made progress in competition without injury, add 5.

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

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

Two situations may be exceptions to the above calculations:

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

If it is difficult to decide which of two groups best fits you, choose the group or outcome that results in the lower heart rate. If in doubt, further individualization with the help of a healthcare practitioner or other specialist familiar with your circumstance and knowledgeable in endurance sports may be necessary.

Once a maximum aerobic heart rate is found, a training range from this heart rate to 10 beats below could be used. So if your maximum aerobic heart rate is determined to be 155, the aerobic training zone would be 145 to 155. However, the more training at 155, the quicker benefits will be realized.

Maximum Heart Rate

Take a group of fit individuals of the same age, gender, and ability, and the maximum heart rates will vary considerably. How is this best determined? There are two ways to find your maximum heart rate. One is by trial, and the other by formula.

The best approach for any fit individual is by trial. Your maximum heart rate for specific activities can be determined following about three to four minutes of maximum (all-out) training, with running being the most effective way to bring the heart rate to the highest level. This is not recommended for those who are not well trained.

A general formula often used for determining your maximum heart rate—for healthy adult male and female athletes not on medication—is 208 minus 70 percent of age (subtract the result of 0.7 times your age from 208). Whether this will be replaced by the new research formula when women are tested is yet to be determined. But even using this or other formulas, those who are fit usually won’t find the same maximum heart rate as performing a trial. In most cases, actual maximum heart rates are higher.

Maximum heart rates vary between different types of activities. Running would produce the highest maximum rate compared to cycling or swimming in the same person. This is due to the increased amount of muscle mass associated with more gravitational stress that accompanies running compared to other activities.

Maximum heart rate may also vary due to a person’s training and stress levels (level of rest), nutritional status (such as hydration), weather (high vs. low humidity), and other factors. This can produce a wide variety of maximum heart rates; a group of 40-year old athletes can have a normal range of maximum heart rates between 160 to 200 beats per minute.

The maximum heart rate can also change with training. In particular, the maximum rate can decrease with successful aerobic training. This is due to increased efficiency of the heart, changes in blood volume and other factors. It’s also been shown that maximum heart rate can increase during periods of less or training. These variations can be about 5%.

How is maximum heart rate useful for those who exercise? While many athletes talk about their levels, often believing that higher is better, which is not necessarily true, there are at least two uses of maximum heart rate.

  • I recommend using a percent of maximum heart rate to obtain a general guideline for training during anaerobic work. This is the training intensity that produces maximum benefits, and rising above this heart rate during an anaerobic workout may produce little or no additional benefits while adding potentially harmful stress. This percentage is 90% of your maximum heart rate. It’s useful during interval training, hill repeats and any anaerobic workout except weight lifting (where monitoring the heart rate is much less important).
  • Another use of maximum heart rate is to compare your rate as determined in training to a general formula that predicts max heart rate. Athletes who don’t come close to their predicted maximum heart rate, compared to the actual one determined during a hard workout, could have a problem with the nervous system (specifically, the autonomic nervous system) which controls the heart, blood vessels and other areas, and can even indicate an increased risk of sudden death (these cases are sometimes associated with very low maximum heart rates).

As researchers continue to find better ways to predict heart and other diseases, each of us bears the ultimate responsibility of taking care of ourselves to avoid disease and live life to its potential. This is accomplished through improvements both in fitness, such as with regular exercise that improves fat burning, and in health which includes diet, nutrition and stress control. The media play a big role in educating the public, but not when they jump to hasty conclusions.

8 Comments

  • Wayne says:

    Hi,

    I know my max heart rate is 210 bpm, how should or should I adjust your 180 formula to reflect my own body

    Wayne

    • Wayne:

      Just follow the formula. Max heart rate is about what heart rate it takes for your heart muscles to start redlining: it says nothing about aerobic activity. The 180-formula describes where your aerobic (Fat-burning) system is working at its best, without using anaerobic activity. The 180-formula has been corroborated by decades of clinical research. The adjustments that you can make will reflect your own body correctly. Trust it.

  • Angie Briley says:

    I’m having issues with a high heart rate during training. I can’t seem to get my heart rate low enough to be in my aerobic zone, which should be between 137-142. I seem to settle into a range of 150-160 most of the time. I did a MAF test in March 2014 and was able to run approx. 9:30/mile at an average HR of 136, but now am running 11:30/mile at an average of 148. I haven’t been injured or sick.

    • Angie:

      Thanks for commenting. Perhaps you should try walking fast. Also, jumping rope doesn’t get your heart rate as high, especially if you stay loose and bouncing on your forefoot. Try to do some MAF work with those exercises before going out running again. You’re probably toeing the line of overtraining, if your MAF speed is dropping like that.

      What’s your current carbohydrate consumption like?

  • Kathy Labus says:

    My Mother is in great physical shape but has had some running injuries, she is 72 years old. What should her number be? Could 108 really be the number? Just want to be sure, as the information on over 65 is not 100% clear. Thank you very much!

    • Kathy:

      Yes, it’s possible. It’s a judgment call as someone gets older: a healthy aerobic system ages much more slowly than a non-healthy one. So when an older person is very healthy, they may have higher-than-expected values.

  • Meg Pennington says:

    Hi,
    I’ve been using this method for the past year and had some success with it, however I have a question regarding my specific HR. I am 38 years old and have a resting HR of 43 and a max of 200. My number has been 150 – however when I race I am able to carry a much higher HR for a longer period of time. The two half ironman I did I carried an average of 180 for the run for both of those races, and the full ironman I carried an average of 166 for the marathon. I have a history of life-threatening asthma as a kid – that is controlled and almost asymptomatic now. I’m not sure if this is a factor or not but my question is because I can carry a higher HR for a long period of time and I don’t feel like I am working at all at my number of 150 should I be training at a different number? Thank you for your help!

  • Philip Lee says:

    Hi,

    I’m 37 years old, 153 lbs, and have been running marathons for over 10 years now, gathering close to 100 half and full marathon races under my belt. I’ve recently tried the MAF method for 2 months and it has not given me any improvements to my race time at all. In fact, my half-marathon time is worse off than it was before. After completing the Toronto half-marathon, my time was 1:53. My PR is 1:40 for the half-marathon; however, I only trained for 2 weeks back with tempo run paces just below my target race pace mixed in with some interval training to attain that time. I’m shocked training for 2 months using the MAF approach with the heart rate formula of 180-age did not improve my time at all. While I was running my half-marathon, I used a Garmin heart rate monitor watch, my heart rate shot up to 200 and held on to 180s for the majority of my run. Does this mean the MAF method formula would not apply to me? Should I be training at a heart rate pace of 200-age instead? I feel I’m an outlier and heart-rate training or MAF method does not apply to me. I’m not even fat, I have a 6 pack, can do 30-40 pull ups straight, and build muscle mass quite easily with my genetic makeup. I’m originally a sprinter in high school and in elementary school I received all 1st place medals and made Toronto district championship races placing in the top 3 in most of my events.

    Any advice on what my target heart rate should be then if my max seems to be near or over 200?

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