Evidence contends lower levels of physical exertion reduce blood pressure (BP) as effectively as more rigorous levels. We compared the effects of low (40% peak oxygen consumption, Vo₂peak), moderate (60% Vo₂peak), and vigorous (100% Vo₂peak) exercise intensity on the BP response immediately following aerobic exercise. We also examined clinical correlates of the BP response.

Subjects were 45 men (mean ± SEM, 43.9 ± 1.4 years) with elevated awake ambulatory BP (ABP, 144.5 ± 1.5/85.4 ± 1.2 mm Hg). Men completed four randomly assigned experiments: non-exercise control and three exercise bouts at low, moderate, and vigorous intensity. All experiments began with a baseline period of seated rest. Subjects left the laboratory wearing an ABP monitor.

Systolic ABP increased 2.8 ± 1.6 mm Hg less after low, 5.4 ± 1.4 mm Hg less after moderate, and 11.7 ± 1.5 mm Hg less after vigorous than control over 9 h (P < .001). Diastolic ABP decreased 1.5 ± 1.2 mm Hg more after low, 2.0 ± 1.0 mm Hg more after moderate, and 4.9 ± 1.3 mm Hg more after vigorous versus control over 9 h (P < .010). Baseline correlates of the systolic ABP post-exercise response to vigorous were fasting glucose (r = -0.415), C-reactive protein (r = -0.362), renin (r = −0.348), fasting insulin (r = 0.310), and fasting low density lipoprotein (r = −0.298) (R² = 0.400, P = .002). Baseline correlates of the diastolic ABP post-exercise response to vigorous were Vo₂peak (r = −0.431), fasting low density lipoprotein (r = -0.431), renin (r = -0.411), fibrinogen (r = 0.369), and fasting glucose (r = −0.326) (R² = 0.429, P < .001).

The antihypertensive effects of exercise intensity occurred in dose response fashion. Clinicians should weigh the benefits and risks of prescribing vigorous exercise intensity for those with hypertension on an individual basis.