Endurance training for 10 weeks in sedentary subjects significantly reduced basal mean blood pressure (86.5 vs 97.5 mm Hg, P<.05) and muscle sympathetic nerve activity (14.0 vs 21.2 bursts/min, P<.02).
Does endurance training improve baroreceptor control of sympathetic nerve activity and lower blood pressure in sedentary subjects?
Endurance training in sedentary subjects lowers basal blood pressure and sympathetic nerve activity while enhancing baroreflex sensitivity, highlighting the autonomic benefits of exercise.
Absolute Event Rate: 86.5% vs 97.5%
p-value: p=<.05
In nine sedentary subjects (16.5 +/- 0.4 years, mean +/- SEM) we measured blood pressure (Finapres device), heart rate (electrocardiogram), and postganglionic muscle sympathetic nerve activity (microneurography from the peroneal nerve) at rest and during intravenous infusion of phenylephrine and nitroprusside. These measurements were performed before and after 10 weeks of endurance training (2 h/d, 5 d/wk) that increased maximum oxygen consumption from 34.8 +/- 2.1 to 40.4 +/- 1.8 mL/kg per minute (P < .02). Basal mean blood pressure and muscle sympathetic nerve activity were lower after than before endurance training (86.5 +/- 2.6 versus 97.5 +/- 1.8 mm Hg, P < .05, and 14.0 +/- 1.8 versus 21.2 +/- 2.3 bursts per minute, P < .02), and the changes in these variables were closely related (r = .95, P < .01). Similar mean blood pressure increases induced by phenylephrine caused greater reductions in heart rate and muscle sympathetic nerve activity after than before endurance training (-8.6 +/- 0.8 versus -6.1 +/- 1.1 beats per minute, P = NS, and -78.0 +/- 4.6% versus -53.6 +/- 4.8%, P < .05). Likewise, similar mean blood pressure reductions induced by nitroprusside caused greater increases in heart rate and muscle sympathetic nerve activity after than before endurance training (18.6 +/- 3.0 versus 12.4 +/- 2.4 beats per minute, P < .05, and 128.1 +/- 26% versus 63.2 +/- 11%, P < .02). No alteration in hemodynamics, oxygen consumption, muscle sympathetic nerve activity, and baroreceptor reflex sensitivity occurred in four other age-matched sedentary subjects studied before and after a 10-week observation period without endurance training.(ABSTRACT TRUNCATED AT 250 WORDS)
Grassi et al. (1994) studied Sedentary (n=13). Endurance training vs. Baseline and observation without training was evaluated on Basal mean blood pressure (p=<.05). Endurance training for 10 weeks in sedentary subjects significantly reduced basal mean blood pressure (86.5 vs 97.5 mm Hg, P<.05) and muscle sympathetic nerve activity (14.0 vs 21.2 bursts/min, P<.02).