The Immediate Antihypertensive Effects of Aerobic Exercise

Abstract

Acute aerobic exercise (AE) produces immediate but transient blood pressure (BP) reductions that persist for up to 24 hr, termed postexercise hypotension (PEH). PEH is strongly correlated with the BP response to AE training. Surprisingly, 33 meta-analyses exist on the BP response to AE training, but none on PEH. PURPOSE: To perform a meta-analysis to determine the effectiveness of PEH as antihypertensive lifestyle therapy among adults with hypertension. METHODS: Databases were searched for controlled PEH trials that included: adults (>19 yr) with hypertension (systolic BP [SBP]/diastolic BP [DBP] ≥140 and/or ≥90 mmHg and/or on BP medication), and BP measured pre- and post-acute AE and control. Study quality was determined using a modified Downs and Black checklist. Analyses incorporated random-effects assumptions. RESULTS: Ten studies and 17 interventions qualified. Subjects (N=260) were middle-aged (41.8±4.2 yr), overweight (28.9±2.3 kg·m-2) adults (24% women, 76% men) with hypertension (SBP/DBP=140.6±9.2/89.2±4.4 mmHg). The AE bout was performed at moderate intensity (5.4±1.3 metabolic equivalents [METs], ~55% maximal oxygen consumption) for 38.0±8.7 minutes, typically on a cycle ergometer (61.9%, k=13). Awake ambulatory BP consisted of 3.1±0.6 measurements/hr at 18.2±4.9 minute intervals over 11.7±4.7 hr. Overall, PEH occurred over the awake hr (SBP/DBP: d+ [95% CI]=-0.76 [-1.03, -0.49]/-0.33 [-0.50, -1.7]; -5.42/-2.12 mmHg), but effect sizes lacked homogeneity (I2 [95% CI]=85.0% [77.4%, 90.1%]/67.9% [46.9%, 80.6%]). PEH was of greater magnitude following higher than lower intensity (>6-<9 METs, -11.4/-5.6 versus 4 METs, -1.6/-0.5 mmHg, p=0.04, respectively), independent of resting BP. For DBP only, PEH was of greater magnitude among trials of lower than higher study quality (-4.0 versus -0.4 mmHg, p=0.03). CONCLUSIONS: On average, the magnitude of PEH was equal to the magnitude of the BP reductions that are reported after AE training (~5-7 mmHg). Furthermore, PEH was of greater magnitude among trials of higher intensity (SBP, ~11 mmHg) and lower quality (DBP, ~4 mmHg). Of note, the antihypertensive benefits of PEH occurred during the awake hr when BP is typically at its highest levels. Future trials are warranted to confirm the effectiveness of PEH as antihypertensive therapy.