Comparison Of Rate-pressure Product Variation During Bench And Leg Press Dynamic Exercise At Different Workloads

Abstract

2393 Rate-pressure product (RPP), has been considered a good predictor of cardiac overload (CO) in strength training. This parameter can be important to improve the security of exercise prescription related to cardiovascular health. PURPOSE: Compare the hemodynamic responses at 40%, 60% and 80% of one-repetition maximum (1RM) among bench press (BP) and leg press 45° (LP) dynamic resistance exercise (RE) in trained subjects. METHODS: Eight apparently healthy male volunteers (21 ± 5yrs; 180 ± 7cm; 78.6 ± 11.4kg; 9.3 ± 4.3%body fat), trained in RE (>6months), were submitted to 1RM test. A familiarization test was performed 48h before the test session (TS). The TS was divided in two days: 1) BP test; 2) LP test. The exercise sessions (ES) were accomplished 48h after the last test, where all volunteers done a maximal number of repetitions for BP and LP exercises, in three consecutive days, at percentage loads established. Subjects were advised to avoid other exercises during the experiment and the Valsalva maneuver. The HR and systolic blood pressure (SBP) were measured with the subjects in the same position of the exercise and immediately after the end of it, using a mercury stand sphygnomanometer, sthetoscope and cardiotacometer. The hemodynamic responses among BP e LP were tested by Wilcoxon Matched Pairs Test (alfa = .05). RESULTS: Comparing the studied hemodynamic parameters found for BP and LP exercises, no statistical difference (p>.05) at low-intensity (40% 1RM) was observed. For moderate-intensity (60% 1RM) it was found differences among all parameters (p<.05). High-intensity (80% 1RM) shown no difference in SBP, although HR and RPP had been different (p<.05), fact that leads to a prevalence of HR in the increase of RPP. In addition, higher HR, SBP and RPP values were observed in LP exercise at all intensities, probably by the effects of exercise positions on the stroke volume. CONCLUSION: The present study found, for low-intensities, the same cardiac overload among BP e LP. However, in moderate-to-high intensity, the CO was higher in LP, although the biggest values of RPP have been found at 60% 1-RM, in both exercises. The results point out to a high cardiac overload at leg press 45° exercise, in despite of the workload imposed.