Author(s)

Chams Eddine Guinoubi, Ammar Nbigh, Youssef Grira, Raouf Hammami, Salma Abedelmalek

Department of Physiology, Faculty of Medicine, Sousse, Tunisia.
Higher Institute of Sports and Physical Education, Kef, Tunisia.
Research Laboratory, “Sports Performance Optimization” National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia.
Research Unit, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia.

The purpose of this study is to evaluate the relationship between %HRmax and %vVO2max at constant efforts made at different intensities. In randomized order, males healthy subjects (Age: 25 ± 7 years, Weight: 70 ± 11 kg, VO2max: 55 ± 8 ml·kg^–1·min^–1) were divided into two groups, a trained one with more than 3 training sessions per week (n = 10) a moderately trained one with 3 drives or less per week (n = 15). The difference between the two groups corresponds to a time to exhaustion above and below 40 min at 80% vVO₂max. All subjects performed 5 tests with a gradual increase in speed of 1 km·h^–1 every 2 min and 4 constant speed tests at 60%, 70%, 80% and 90% VO₂max. All test were performed at the same time of day (i.e., 18:00 h). The results of this study showed that eighteen collective regressions including different independent variables were developed to predict %HRmax. The individual equations developed, have r values between 0.974 and 0.993 and Syx, between 1.2 and 1.9 ml·kg^–1·min^–1, they are more accurate than the collective equations (one equation for all subjects) with r values between 0.81 to 0.89 and Syx, between 4.1 and 5.3 ml·kg^–1·min^–1. In conclusion, this study has demonstrated that the model of predictions of %HRmax from %vVO₂max in triangular tests were not appropriate for rectangular efforts. From the equations developed, we find that the time to exhaustion at 90% vVO₂max is the best predictor of level of endurance then the time limit to 80% vVO₂max.

Heart Rate Percent; Treadmill Exercise; Prediction; Triangular Test

Guinoubi, C. , Nbigh, A. , Grira, Y. , Hammami, R. and Abedelmalek, S. (2012) Prediction of maximal heart rate percent during constant intensity efforts on trained subjects. Open Journal of Internal Medicine, 2, 190-197. doi: 10.4236/ojim.2012.24031.