Post-Exercise Hypotension in Elderly Hypertensive Men

Overview

The purpose of this study is to compare the effects of two exercise protocols on post-exercise blood pressure versus a control group in elderly hypertensive men. Participants are allocated to all groups: control group and two experimental exercise protocols, in a random order. In the control group, participants remain resting sitting, and, in the exercise protocols, participants practice exercise bouts of aerobic exercise or a combination of resistance and aerobic exercises. In order to standardize baseline conditions, before the sessions subjects remain sitting quietly for 20 minutes. After each exercise protocol, participants have 60 minutes for recovery and, simultaneously, they have BP measured every 5 minutes. After the exercise sessions or control, an equipment for 24 hours ambulatory BP monitoring is installed in every participant.

Hypertension has high prevalence and low rate of control, and is a major modifiable risk factor and public health problem. Regular physical exercise is a relevant non-pharmacological option for prevention and treatment of hypertension. Several studies demonstrated a reduction in blood pressure (BP) following different exercise protocols, and the decrease may be the result of the summation of hypotensive effects that occur in the hours following the workout. The reduction resulting from a single exercise session is called post-exercise hypotension (PEH) and has been investigated among hypertensive subjects. However, to achieve clinical relevance the PEH should reach a significant magnitude and the reduction should be sustained for a longer period. Previous studies showed the positive effects of aerobic exercise on post-exercise hypotension in hypertensive subjects. However, there is lacking evidence regarding the effects of a single session of aerobic and resistance exercise combined, and the duration of its effect in 24 hours blood pressure in elderly hypertensive subjects. The study is an open, crossover randomized clinical trial, with elderly men allocated to three arms, in a random order: * Aerobic training session * Combined resistance training and aerobic session * Control session After each exercise session, participants have 60 minutes for recovery, performed in the sitting position, with BP measurements every 5 minutes. In addition, participants have measured BP using 24h ambulatory BP monitoring. At the end of the trial, participants will have completed all three experimental protocols: a non-exercise control session, of sitting rest, and two exercise bouts, one of aerobic exercise and a combined resistance and aerobic exercise, with seven days of washout period among sessions. All experiments will be conducted at the same time of day to account for diurnal BP variation. Before the experimental sessions, participants are enrolled in three pre-intervention tests: a familiarization session, cardiopulmonary exercise testing and one maximum repetition strength test (1RM). The aerobic sessions last for 45 minutes, as well as the resistance exercises, and the session of control.