Blood Pressure Reduction Following The Accumulaton Of Short Physical Activity Sessions Versus A Continuous Physical Activity Session In Prehypertension

Abstract

Despite limited research, the accumulation of physical activity has been recommended for the treatment of prehypertension. The purpose of this study was 1) to compare the duration and magnitude of blood pressure (BP) reduction following the accumulation of physical activity (PAaccum) vs. a single continuous physical activity session (PAcont), 2) to investigate the BP response during the rest periods between short sessions within the PAaccum, and 3) to investigate sympathetic modulation (SM) as a possible mechanism for BP reduction in prehypertension. Procedures include 1) BP screening, 2) maximal graded exercise test, 3) treatments (PAaccum, 4x10-min walk at 50% VO2peak; PAcont, 40-min walk at 50% VO2peak; and control), and 4) 12-hr ambulatory BP, and SM measurements via heart rate variability. In this randomized within-subjects design, 20 prehypertensive completed the study. Systolic (S) BP was reduced -5.4+1.7 mm Hg for 11 hrs following PAaccum and -5.6+1.6 mmHg for 7 hrs following PAcont. Diastolic (D) BP was reduced -3.4+1.3 mmHg for 10 hrs following PAaccum and -3.1+1.3 mmHg for 7 hrs following PAcont. In PAaccum, the change in sympathetic modulation was correlated with both SBP and DBP reductions. In PAcont, the change in sympathetic modulation was correlated with DBP reduction. SBP was decreased following the third short session within the PAaccum compared to the baseline. No significance was found in either DBP or SM during the rest periods between short sessions. In conclusion, the accumulation of PA appears more effective than a continuous session in the management of prehypertension. There is an additive effect of successive short sessions within the accumulation of physical activity on blood pressure reduction. Sympathetic modulation was associated with BP reduction following each PA treatment.