Editor's Note:  This article will have you believe that the simple formula for calculating maximum heart rate isn't as accurate as this "new method." However, the new method has a large margin of error and when taken into account, basically gives you the same number as the simple formula! I say keep your life simple - stick with the simple formula.

You've probably been told that the best way to predict your maximal heart rate — the maximum number of times your heart can beat each minute — is to subtract your age from the number 220.

Used by many fitness professionals to design training routines, the formula also forms the basis for the programs used on many aerobic exercise machines.

Heart Rate
However, new research shows that this equation overestimates maximal heart rate in younger people and underestimates it in older people. It calls into question the validity of exercise routines using your predicted maximum heart rate to determine how hard you should train.

The original formula is based on data compiled in 1971, although scientists have been attempting to predict maximal heart rates since the late 1930's. Yet despite its popularity, the validity of the equation has never been tested in a sample that includes a sufficient number of older adults.

In fact, when Dr. Robert Robergs recently analyzed the data on which the original formula was based, he ended up with a totally different equation!

Moreover, Swedish exercise scientist Per Olof Astrand reports that the average drop in maximal heart rate for women is 12 beats in 21 years and 19 beats in 33 years. For men, the drop is 9 beats in 21 years and 26 beats in 33 years.

In other words, your maximum heart rate doesn't drop by one beat per year (as the old formula predicts that it does). Moreover, the rate of decline appears to differ in men and women.

New Formula for Calculating Maximum Heart Rate
The new formula, though still plagued by some of the problems associated with the previous version, comes from a study published in the Journal of the American College of Cardiology. Researchers from the University of Colorado at Boulder analyzed the data from 351 studies to devise the new equation.

Subsequently, it was tested in the laboratory where maximal heart rate was measured in 514 healthy subjects. The new formula requires that you multiply your age by 0.7, and take this number away from 208.

The table below shows you the difference between predicted maximal heart rates obtained using both the new and old equations.

TABLE 1. A comparison of the old and new formula for predicting maximal heart rate.

The bottom line is that the new formula does appear to be more accurate than the previous version. However, there's still a large margin of error — estimated by some to be plus or minus 6-7 beats per minute.

In other words, if your predicted maximal heart rate is 180 beats per minute, it could really be anywhere between 173 and 187. This is an important fact to consider if you base your training program on a percentage of your predicted maximal heart rate.
 

Read other articles by Christian Finn

About the Author

Christian Finn is a Certified Personal Trainer and holds a masters degree with distinction in exercise science. He's lectured at a number of universities and private training organizations around the United Kingdom on fitness training, weight loss and the effective use of nutritional supplements. He writes extensively on the subject and his articles have been published in numerous magazines, leading industry journals and websites worldwide, including Men's Health, Men's Health Muscle, Fit Pro (April/May 2001), CAM magazine (February 2003), Image (January 1997), Zest (March 2004), and Body Life magazine (March/April 1997). He was also featured in the July 2004 issue of Muscle & Fitness (UK edition). His website, TheFactsAboutFitness.com, is dedicated to providing its members up-to-date, unbiased information and research on the world of fitness.

References

Tanaka, H., Monahan, K.D., & Seals, D.R. (2001). Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 37, 153-156