Selection of Suitable Maximum-heart-rate Formulas for Use with Karvonen Formula to Calculate Exercise Intensity

The Karvonen formula, which is widely used to estimate exercise intensity, contains maximum heart rate, HR_max, as a variable. This study employed pedaling experiments to assess which of the proposed formulas for calculating HR_max was the most suitable for use with the Karvonen formula. First, two kinds of experiments involving an ergometer were performed: an all-in-one-day experiment that tested eight pedaling loads in one day, and a one-load-per-day experiment that tested one load per day for eight days. A comparison of the data on 7 subjects showed that the all-in-one-day type of experiment was better for assessing HR_max formulas, at least for the load levels tested in our experiments. A statistical analysis of the experimental data on 47 subjects showed two of the HR_max formulas to be suitable for use in the Karvonen formula to estimate exercise intensity for males in their 20 s. In addition, the physical characteristics of a person having the greatest impact on exercise intensity were determined.