Mechanisms and Exercise Characteristics Influencing Postexercise Hypotension

Abstract

Arterial blood pressure (BP) can be reduced below pre-exercise levels after a single bout of exercise. This post-exercise reduction in BP is termed “postexercise hypotension” (PEH). The aim of this review was to present current studies exploring the mechanisms of PEH and discuss potential factors influencing the magnitude and the duration of PEH. The mechanisms underlying PEH point to centrally mediated decreases in sympathetic nerve activity (due to decreased neural afferent input to the nucleus tractus solitarius and baroreceptor resetting to lower BP) and to local vasodilatory mechanisms (histamine binding to H1 and H2 receptor). The exercise characteristics (intensity, duration, and mode) and the participant characteristics (such as fitness status, baseline BP, body adiposity, gender, and hydration status) influence PEH. Earlier studies using aerobic exercise in normotensive and hypertensive individuals, suggested that PEH is a low-threshold event; however, most recent studies seem to agree, that at least in the first few post exercise hours, PEH is exercise intensity dependent. Studies using intermittent aerobic, resistance, and concurrent exercise (combined aerobic and resistance) also showed promising results on PEH. Equivocal results regarding the duration and magnitude of PEH are possibly associated with the muscle mass activated, the weight-load, and/or the number of repetitions and sets used in the different studies. Although most studies suggest that moderate to high intensity exercise induces greater PEH in normotensive and hypertensive individuals, exercise prescription should be individualized and caution should be taken in patients with multiple risk factors and chronic diseases.