Max Heart Rate

Interesting article by Tanaka et al. in the Journal of American College of Cardiology. They did a study on Maximal Heart Rate (MHR). Current formula to estimate MHR is 220 – age. These guys conducted a study in two stages. The first stage was meta-analysis of the existing literature with strict selection criteria. Mean MHR values were collected from 351 studies involving 492 groups and 18,712 subjects.

Because the studies included in the meta-analysis used different terms to describe the aerobic exercise status of their subject groups, the authors classified and analyzed the groups into three categories: 1) endurance-trained, referring to regular performance of vigorous endurance exercise 3 times per week for over one year; 2) active, referring to occasional or irregular performance
of aerobic exercise 2 times per week and 3) sedentary, referring to no performance of any aerobic exercise.

Maximal heart rate was strongly and inversely related to age in both men and women with correlation coefficient of - 0.9. The rate of decline was not different between men and women or among sedentary, active and endurance-trained subjects. Further analysis revealed that age alone explained about 80% of the individual variance in MHR.

The authors derived the new formula: MHR = 209 – 0.7 x age. During the second stage it was tested on 514 healthy subjects and the conclusions from the meta-analysis were confirmed: the formula derived from the experimental data was virtually identical to the one obtained from statistical data and the MHR was mostly determined by age, with standard deviations ranging from 7 to 11 beats per minute.

With the old formula NHR is overestimated in young adults and underestimated in older age. The difference does not seem to be that large, and at age 70 the difference is 10 beats/min. However, as the author commented, considering the wide range of individual subject values for MHR - standard deviation of 10 beats per minute - the underestimation of MHR could be 20 beats/min for some older adults. They also commented that all equations have limitations because of the inter-individual variability, and direct measurement of MHR should be undertaken when possible.

In short, HR decreases with age no matter if you exercise or not. The equation currently used to calculate MHR underestimates it, and if you are older than 45 years old you might be getting less training than you think. To get the best value test your MHR from time to time.

Tanaka H et al. Age-Predicted Maximal Heart Rate Revisited
J. Am. Coll. Cardiol. 2001;37;153-156