the myth of "Maximum Heart Rate = 220-Age"
You’ve probably heard of the “220-your age” formula for estimating maximum heart rate. Unfortunately, this formula is not very useful because it can easily miss more than 20 beats on the high or low side. For me at 54, this formula says my max heart rate should be 166, but I know from more accurate testing that it’s at least 25 beats higher than that.
In books, on exercise machines, and on gym walls, you’ll often see charts of suggested exercise intensity that are based on your 220-year age. He is also on calculators all over the web. You would hardly sweat if you exercised at those levels. But more importantly, for some people the opposite is true and their maximum heart rate may be more than 20 beats lower than the formula predicts. If they exercised at the levels in the charts, their intensity might be too high, especially for anyone with a medical condition.
This formula is often cited without any warning about its possible inaccuracy, and in addition to the inaccuracy, it turns out to have little scientific basis. [Kolata, 2003]. Some people are aware that its original authors never intended 220-age to be a universal formula (it was intended to arrive at a safe level of exercise for cardiac rehab patients and was based on a not very large sample of subjects). But the problem is also in the basic assumption that the maximum heart can be predicted only based on age. If you think about it, it sounds silly: Regardless of family history, fitness level, whether we’re tall or short, underweight or overweight, etc., we all have exactly the same heart rate at a certain age, and the rate maximum heart rate decreases. with age in all of us at exactly the same rate?
More recent studies have attempted to review this concept in a larger sample of the population. For example, in one study, based on thousands of male and female subjects, ages 18 to 81, the authors proposed a “best fit” equation of:
Maximum heart rate = 208 -0.7xAge.
However, if you look at the data it’s based on, it looks like a cloud with only a vague trend toward heart rate decline with age; there is a lot of dispersion. The new formula is slightly more accurate than the old one, but it can still predict below or above maximum heart rate by 20 beats or so. [Tanaka, 2001].
A recent review of many attempts to find a formula to predict maximum heart rate concluded that there is no sufficiently accurate formula to predict maximum heart rate from age alone. [Robergs, 2002]. In my opinion neither is possible due to the large amount of scatter in the data. Exercise physiologist Dr. Fritz Hagerman, who has studied world-class rowers for three decades, has said that the idea of a formula to predict an individual’s maximum heart rate is ludicrous: He has seen 20-year-old Olympic rowers with heart rates maxims. of 220, and others on the same team and with the same ability, with maximum rates of only 160 [Kolata, 2001].
Many books have tables with elaborate training programs based on various intensity zones, all based on maximum heart rate. It may all sound very scientific, but it’s not worth it if it’s based on an inaccurate number.
Another misconception I have come across is that the problem with the 220 year old formula is solved by using the “heart rate reserve” or Karvonen formula. In that formula, exercise intensity is expressed as a percentage of your “reserve capacity” between your resting heart rate (RHR) and your maximum heart rate (MHR):
Target Heart Rate = X% of (MHR-RHR) +RHR
Where X% is the desired percentage. This is a useful formula because the intensities of it are related to a percentage of your heart rate corresponding to your VO2Max maximum oxygen update, which many exercise physiologists like to use. But Karvonen’s formula still needs an accurate estimate of your maximum heart rate. If you enter an inaccurate number based on an age-related prediction, such as 220 years, the result will still be inaccurate.
Heart rate training can be a useful tool, if based on a good estimate of what is a valid intensity level for you. Maximum heart rate can be accurately measured in a lab, but for most of us that’s an expensive option. You can estimate other useful parameters such as lactate threshold heart rate from self-administered tests (see, for example, [Carmichael, 2003]) and this can be used for heart rate based training. But for those of us who are primarily interested in fitness, I question the need. I’m a “perceived level of exertion” guy. On easy cardio days, my pace is comfortable. On hard days it feels hard, and doing intervals is very hard. This leads to good and steady progress.
References
-Carmichael, Chris and Jim Rutberg, The Ultimate Ride: Get Fit, Get Fast, and Start Winning with the World’s Top Cycling Coach, Grosset & Dunlap, 2003.
-Kolata, G, “Maximum Heart Rate Theory Called into Question,” The New York Times Health Page, April 24, 2001.
-Robergs, R and Landwehr, R, “The surprising history of the ‘HRmax= 220-age’ equation”, Journal of Exercise Physiology Online, 5(2), 2002.
-Tanaka H, Monahan K, Seals D, “Review of Age-Predicted Maximum Heart Rate,” Journal of the American College of Cardiology, 37(1), 153, 2001.