Immediate post-isometric exercise cardiovascular responses are associated with training-induced resting systolicblood pressure reductions

Purpose: The purpose of this study was twofold: (1) to investigate the effect of four-weeks of bilateral-leg isometric exercise training on the immediate isometric post-exercise cardiovascular responses, and (2) to ascertain whether any changes in immediate post-exercise cardiovascular responses may be associated with training-induced adaptations in resting blood pressure.

Methods: Thirteen normotensive males completed both isometric exercise training (IET) and control conditions, which were separated by 6 weeks. Participants performed a total of twelve training sessions; 4 * 2-minute bilateral-leg isometric exercise bouts separated by 3-minute rest periods, 3 days.wk-1.

Results: 4-weeks of bilateral-leg IET resulted in a reduction in resting SBP (120 ± 12 to 115 ± 12 mmHg, p = 0.01). The intercept of the 5-minute post-exercise systolic blood pressure slope was lower (p = 0.015) following the 4-week training intervention. Individual changes in immediate post-exercise response SBP were also significantly correlated with reductions in resting SBP following 4-weeks of training. There were significant differences in the slopes of the first vs. final post-exercise BRS response (p = 0.009), and the intercepts of the HRR slopes (p = 0.04) recorded during the 5-minute post-exercise periods

Conclusions: Four weeks of IET altered immediate cardiovascular responses to an individual IET session. Altered immediate responses were also associated with training induced reductions in resting SBP. To our knowledge, this is the first evidence suggesting very short-term (immediate) cardiovascular responses may be important in defining chronic reductions in resting blood pressure following a period of IET.