Short Versus Long Duration Moderate Intensity Dynamic Exercise And Postexercise Hypotension

Abstract

0691 PURPOSE: The acute effects of short duration, moderate intensity exercise on BP are unclear. We compared the effects of a short and longer session of moderate intensity endurance exercise on BP in men who exhibit postexercise hypotension (PEH). METHODS: Subjects (n = 17) (Mean ± SEM, 45.7 ± 2.1yr) had high normal to Stage 1 hypertension (142.9 ± 2.1/85.9 ± 1.5 mmHg). They randomly completed three experiments: a 30 min control session of seated rest and two moderate intensity (60% maximal oxygen consumption) cycle exercise bouts, a 15 min short and a 30 min long session. Experiments began with a baseline period and were performed at the same time of day and separated by > 2 d. Subjects wore an ambulatory BP monitor after the experiments. RMANOVA tested if BP differed over time and between experimental conditions. RESULTS: For 5 hr, average SBP increased less from baseline for short (0.3 ± 1.8 mmHg) and long (2.9 ± 1.9 mmHg) duration exercise compared to control (10.3 ± 1.3 mmHg) (P <0.01); and DBP decreased more from baseline for long (−4.2 ± 0.9 mmHg) than short (−0.6 ± 1.2 mmHg) duration exercise and control (1.2 ± 0.8 mmHg) (P <0.01). For 14 hr, average SBP decreased more from baseline for long (−1.0 ± 2.2 mmHg) than short (3.9 ± 2.7 mmHg) duration exercise and control (8.2 ± 1.9 mmHg) (P <0.01); and DBP decreased more from baseline for long (−7.1 ± 1.3 mmHg) than short (−3.7 ± 1.9 mmHg) duration exercise and control (−0.1 ± 0.8 mmHg) (P <0.01). CONCLUSIONS: Over the course of 5 hr, BP was lower following a bout of short and long duration endurance exercise compared to control among men with hypertension. Short duration, moderate intensity dynamic exercise is a sufficient stimulus to evoke PEH, but the BP reductions are greater and more sustained with long than short duration exercise. Supported by an American Heart Association Grant-in-Aid # 0150507N