Blood Pressure Responses to Acute and Chronic Exercise Are Related in Prehypertension

Abstract

Aerobic exercise is recommended as a way to prevent hypertension. However, about 25% of individuals receive minimal antihypertensive benefits associated with chronic exercise training. Thus, we attempt to identify those "nonresponders" to chronic exercise on the basis of their blood pressure (BP) responses to acute exercise (single session). Our primary objective was to correlate the magnitude of BP decrease after acute exercise to the magnitude of BP reduction after chronic exercise. Our secondary objective was to examine the correlates of BP reduction after acute and chronic exercise. Seventeen prehypertensive (120 to 139/80 to 89 mm Hg) males and females (45-60 yr old) underwent acute exercise assessments before an 8-wk walking/jogging program (four times per week, 30 min per session, 65% maximum oxygen consumption). BP, hemodynamics, HR variability, and baroreflex sensitivity were assessed before and after acute exercise and chronic training. BP was significantly reduced -7.2 ± 1.2/-4.2 ± 1.0 and -7.0 ± 1.4/-5.2 ± 1.2 mm Hg relative to baseline after acute (30 min at 65% maximum oxygen consumption) and chronic exercise, respectively (P < 0.01). The magnitude of change in systolic BP after acute exercise was strongly correlated with change in resting systolic BP after chronic training, r = 0.89, P < 0.01. A similar correlation was observed with diastolic BP, r = 0.75, P < 0.01. After acute exercise, significant reductions in total power (ms(2)) and baroreflex sensitivity were observed in both sexes (P < 0.01). However, after chronic exercise, only men demonstrated a significant reduction in the low-frequency-to-high-frequency ratio (-36%), P < 0.01. The magnitude of the acute BP-lowering with exercise may predict the extent of BP lowering after chronic training interventions in prehypertensive individuals.