Aftereffects of exercise and relaxation on blood pressure.

OBJECTIVE To study the acute aftereffects of exercise and relaxation, performed alone and in combination, on blood pressure (BP) measured at baseline and during stressful conditions. DESIGN Clinical trial with comparison of groups and repeated measures in each group. SETTING Exercise Hemodynamic Laboratory, University of São Paulo, Brazil. PARTICIPANTS Fourteen normotensive (NT) and 16 essential hypertensive (HT) subjects. INTERVENTIONS Four random experimental sessions: relaxation (RX-20 min); exercise [EX-cycle ergometer, 53 min, 50% peak oxygen uptake (VO2peak)]; exercise plus relaxation (EX+RX); and control (C-73 min rest). Measures were taken before and after interventions at baseline and during Stroop color test. MAIN OUTCOME MEASURES Auscultatory and plesthysmographic BPs. RESULTS Systolic and diastolic BPs decreased significantly after all the interventions. The decreases in both BPs were significantly greater after the EX+RX session, and were also greater in the HT (EX+RX session, -10+/-1/-7+/-1 and -15+/-2/-8+/-1 mm Hg for the NT and HT, respectively). During mental stress, systolic BP increased significantly and similarly after all the experimental sessions. Diastolic BP also increased significantly during stress; however, the increase was significantly greater after the RX session. At the end of the mental stress, diastolic BP was significantly lower after the EX (74+/-3 mm Hg) and EX+RX (72+/-3 mm Hg) sessions than after the C (79+/-3 mm Hg) and RX (78+/-3 mm Hg) sessions. CONCLUSIONS In NT and HT subjects, a single bout of exercise or relaxation has hypotensive effects, further enhanced by their combination, and greater in the HT. Moreover, exercise performed alone or in combination with relaxation decreases systolic and diastolic BPs during mental stress.