Most regular exercisers have, at one point or another, tried to guage their output based upon a certain percentage of their maximal heart rates say between 50 and 70 percent. But the figure they use (220 beats per minute minus one s age) to calculate this percentage is wrong, according to Gretchen Reynold s blog in The New York Times.
Although the old formula is simple and thus appealing, the new calculation is more nuanced, she notes. A study by Dr. BM Nes from the Norwegian College of Science and Technology and colleagues, published in the Scandinavian Journal of Medicine & Science in Sports, examines the validity of this algorithm.
As quoted by Ms Reynolds, Dr. Wisloff, one of the researchers said The traditional formula can underestimate heart rate max by up to 40 beats per minute in seniors and starts becoming inaccurate already at the age of 30 or 40 years. After studying approximately 3300 men and women between 19 and 89 years of age, they found that a better equation is 211 beats per minute minus 0.64 times one s age. Further, they noted that neither age nor physical activity confounded the results. (We d like to point out that a subtle shift from 0.64 to would not change the results very much and would make calculations so much simpler).
So how different would the numbers be with the old and new formulas? For a 60 year-old man, for example, the older formula would give a maximal heart rate of 220 minus 60, or 160 beats per minute. The new formula results in 173 beats per minute.
ACSH s Dr. Ruth Kava notes While this difference isn t huge, it will make a difference for those individuals who use maximal heart rate to determine the length or intensity of their exercise routines. However, it s not really necessary to have that figure so exact, as gauging one s exercise intensity by how you feel doing it is likely just as relevant to the benefits you re gaining.