Synergistic Effects of Low-Intensity Exercise Conditioning and β-Blockade on Cardiovascular and Autonomic Adaptation in Pre- and Postmenopausal Women With Hypertension

The effects of a 12-week low-intensity exercise conditioning program (walking) on blood pressure (BP), heart rate (HR), rate-pressure product (RPP), and cardiac autonomic function were measured in 40 sedentary women with hypertension. Women were assigned to either an exercise group (n = 20) or a control group (n = 20), matched for beta-blockade treatment. They underwent testing at the beginning and at the end of the 12-week study period in three conditions: supine rest, standing, and low-intensity steady state exercise. The exercise group participated in a 12-week, low-intensity walking program, while the control group continued with usual sedentary activity. Compared with the control group, women in the exercise group showed reductions in systolic and diastolic BP and RPP (i.e., the estimated cardiac workload). beta-Blockers increased baroreflex sensitivity and lowered BP and HR in all participants; however, those in the exercise group showed the effects of both treatments: a greater reduction in HR and RPP. The combination of exercise training and beta-blockade produces cardiac and autonomic adaptations that are not observed with either treatment alone, suggesting that beta-blockade enhances the conditioning effects of low-intensity exercise in women with hypertension.