Evaluating the Accuracy of Maximum Heart Rate Prediction Equations to Adjust the Intensity of Physical Activity in 8–12-Year-Old Students

Background and Objective: Cardiovascular and sports experts recommend the use of oxygen consumption cost indicators, heart rate and fatigue index to control work pressure in sports and rehabilitation. Meanwhile, it is very common to control the intensity of exercise by heart rate index. However, the maximum heart rate (HRmax) must first be measured or estimated as the basis for the calculations. The purpose of the present study is to evaluate the validity of HRmax estimation equations in healthy children. Materials and Methods: The HRmax was measured and estimated in 205 healthy boys between 8 and 12 years old by two methods, Bruce's incremental exercise test and special equations for children. In order to compare the estimated and measured HRmax, Pearson's correlation, t-correlated and root mean square error (RMSE) were used. Results: A weak correlation between estimated and measured HRmax was observed (R=0.09-0.18). A significant difference was observed between the estimated and measured HRmax (beats per minute = 1.4-4.8) (P<0.05). So, the Nikolaidis equation led to a significant overestimation and the Shargal and Gelbert equations led to a significant underestimation of the HRmax. Also, the root mean square error values for HRmax estimation equations were high (RMSE = 6.9 - 7.4 beats per minute). Conclusion: Considering the ineffectiveness of foreign equations for estimating the HRmax in Iranian children, it is recommended to design native equations for estimating the HRmax for Iranian children.