The Influence of Exercise Intensity on Postexercise Baroreflex Sensitivity

摘要

Purpose: The purpose of this study was to investigate the influence of exercise intensity on postexercise supine and tilt baroreflex sensitivity (BRS). Method: Nine healthy, active men performed 2 conditions of interval cycling of 40% maximal work rate (WRmax) and 75% WRmax of matched work done and a control condition of no exercise in a counterbalanced order. BRS outcome measures were determined at preexercise and postexercise up to _24 hr in supine and tilt positions. R-R interval and blood pressure data were collected over consecutive 10-min periods and were analyzed by Fast Fourier transformation analysis. Results: A fully repeated analysis of variance revealed a significant interaction (p,.05) between time and condition in supine for BRSaLF, F(3, 134) = 5.19, p,.05, ES =.39, and BRSTFTG, F(3, 134) = 5.65, p,.05, ES =.41, and in tilt for BRSUpUp, F(3, 134) = 3.54, p,.05, ES =.31, BRSDownDown, F(3, 134) = 5.94, p,.05, ES =.43, BRSaLF, F(4, 134) = 6.23, p,.05, ES =.44, and BRSTFTG, F(4, 134) = 9.22, p,.05, ES =.54. There were significant differences (p,.05) between condition comparisons at +15 min and between control and 75% WRmax and between the 40% WRmax and 75% WRmax conditions at +60 min. At +15 min, BRS was lower in the 75% WRmax condition compared with the 40% WRmax condition and the control condition, and it was lower in the 40% WRmax condition than in the control condition. Conclusion: The findings demonstrate an intensity-dependent relationship in the BRS response following exercise.