Acute hypotensive effect of dynamic, isometric and combined (dynamic + isometric) resistance exercise in medicated hypertensives men: hemodynamic and autonomic mechanisms

Abstract

Dynamic and handgrip isometric resistance training have been shown to decrease blood pressure (BP) by different mechanisms, suggesting that their combination may produce a greater hypotensive effect in hypertensives (HT). Additionally, each resistance exercise session may produce post-exercise hypotension (PEH - i.e. a decrease in BP during recovery), which has clinical relevance when presents significant magnitude and persists for many hours. In addition, PEH can be used to predict the chronic BP responses to training, which justifies studying PEH before investigating the chronic effects of training that implies in more time and investment. A single session of dynamic (DE) and isometric handgrip (I-hE) resistance exercises cause PEH, but its duration and mechanisms need to be studied. In addition, no previous study has investigated the effects of the combination between these exercises (CE), which may potentiate the hypotensive effect. Thus, this study will evaluate and compare the effects of a single session of DE, I-hE and EC on post-exercise BP and its mechanisms. Medicated hypertensives men will undergo one of the following sessions (raffle): control (70 min seated rest); DE (8 exercises, 3 sets, repetitions to moderate fatigue, 50% of 1RM); I_hE (4 sets, unilateralhandgrip, 2 min, 30% of MVC); and EC (DE + I-hE). In each session, before and after the interventions, the following variables will be measured: clinic and ambulatory BP; systemic hemodynamics (cardiac output, systemic vascular resistance, heart rate and stroke volume); local hemodynamics (forearm blood flow and endothelial function);and cardiovascular autonomic modulation (sympathetic and parasympathetic modulations). ANOVA, considering p<0.05. (AU)