Postexercise hypotension due to resistance exercise is not mediated by autonomic control: A systematic review and meta-analysis.

Abstract

Changes in autonomic control have been suggested to mediate postexercise hypotension (PEH). We investigated through meta-analysis the after-effects of acute resistance exercise (RE) on blood pressure (BP) and autonomic activity in individuals with normal and elevated BP. Electronic databases were searched for trials including: adults; exclusive RE interventions; and BP and autonomic outcomes measured pre- and postintervention for at least 30min. Analyses incorporated random-effects assumptions. Thirty trials yielded 62 interventions (N=480). Subjects were young (33.6±15.6yr), with systolic BP (SBP)/diastolic BP (DBP) of 124.2±8.9/71.5±6.6mmHg. Overall, RE moderately reduced SBP (normal BP: ~1 to 4mmHg, p<0.01; elevated BP: ~1 to 12mmHg, p<0.01) and DBP (normal BP: ~1 to 4mmHg, p<0.03; elevated BP: ~0.5 to 7mmHg, p<0.01), which was in general parallel to sympathetic increase (normal BP: g=0.49 to 0.51, p<0.01; elevated BP: g=0.41 to 0.63, p<0.01) and parasympathetic decrease (normal BP: g=-0.52 to -0.53, p<0.01; elevated BP: g=-0.46 to -0.71, p<0.01). The meta-regression showed inverse associations between the effect sizes of BP vs. sympathetic (SBP: slope-0.19 to -3.45, p<0.01; DBP: slope-0.30 to -1.60, p<0.01), and direct associations vs. parasympathetic outcomes (SBP: slope 0.17 to 2.59, p<0.01; DBP: slope 0.21 to 1.38, p<0.01). In conclusion, changes in BP were concomitant to sympathetic increase and parasympathetic decrease, which questions the role of autonomic fluctuations as potential mechanisms of PEH after RE.