Reliability and Time Course of Postexercise Hypotension during Exercise Training among Adults with Hypertension

Postexercise hypotension (PEH), or the immediate decrease in blood pressure (BP) lasting for 24 h following an exercise bout, is well-established; however, the influence of exercise training on PEH dynamics is unknown. This study investigated the reliability and time course of change of PEH during exercise training among adults with hypertension. PEH responders (n = 10) underwent 12 weeks of aerobic exercise training, 40 min/session at moderate-to-vigorous intensity for 3 d/weeks. Self-measured BP was used to calculate PEH before and for 10 min after each session. The intraclass correlation coefficient (ICC) and Akaike Information Criterion (AIC) determined PEH reliability and goodness-of-fit for each week, respectively. Participants were obese (30.6 ± 4.3 kg∙m^-2), middle-aged (57.2 ± 10.5 years), and mostly men (60%) with stage I hypertension (136.5 ± 12.1/83.4 ± 6.7 mmHg). Exercise training adherence was 90.6 ± 11.8% with 32.6 ± 4.2 sessions completed. PEH occurred in 89.7 ± 8.3% of these sessions with BP reductions of 9.3 ± 13.1/3.2 ± 6.8 mmHg. PEH reliability was moderate (ICC ~0.6). AIC analysis revealed a stabilization of maximal systolic and diastolic BP reductions at 3 weeks and 10 weeks, respectively. PEH persisted throughout exercise training at clinically meaningful levels, suggesting that the antihypertensive effects of exercise training may be largely due to PEH. Further studies in larger samples and under ambulatory conditions are needed to confirm these novel findings.