Re-Visiting Maximal Heart Rate Prediction Using Cross-Validation in Population Aged 7-55 Years

The primary purpose of the present study was to re-visit HR_max prediction by two commonly used equations (i.e., Fox's and Tanaka's equation) compared to the direct measured HR_max using the large sample size of Asians. The second aim of the study was to focus on suggesting new equations for the Asian population by separating gender and specific age groups. A total of 672 participants aged from 7 to 55 years were recruited for the study (male: 280 and female: 392), and the maximal graded exercise test with Bruce protocol was used to measure HR_max. All data obtained from the study were analyzed by SPSS 25.0. Additionally, three statistical analysis methods (i.e., Mean Absolute Percent Errors (MAPE), Bland-Altman plots, and equivalence testing) were utilized to confirm the consistency between the measured HR_max and the two prediction equations. The main finding was that two equations showed significant differences in predicting the HR_max of Korean aged from 7 to 55 years. The outcome of children aged from 7 to 14 was a different fit in the agreement compared to other age groups. Fox's equation had the best fit in the average of the difference closer to zero and completely included within the equivalence zone, but females over 15 years old revealed higher errors than males in the values calculated by the two equations compared to the direct measured HR_max. Consequently, the study demonstrated that both equations tended to overestimate the HR_max for males and females over 15 years old, and the two universal equations were not suitable to predict the HR_max of Koreans except for children aged from 7 to 14 years. The new HR_max prediction equations suggested in this study will more accurately predict the HR_max of Asians, and additional analyses should be examined the cross-validity of the developed HR_max equation by age and gender in the future study.