Association between cardiac autonomic control and blood pressure response to resistance training in adults with pharmacologically treated hypertension

This study aimed to assess the acute cardiac autonomic responses to high and low intensity resistance training and their association with post exercise hypotension in adults with pharmacologically treated hypertension. This randomized clinical trial included 31 participants with pharmacologically treated hypertension. The effects of two resistance training sessions performed at high intensity (80% of 1RM) and low intensity (40% of 1RM), matched for total training volume, were compared. Blood pressure and heart rate variability were measured before and after exercise. Significance level was set at 5%. No significant interaction was observed for any of the variables (p > 0.05). Both intensities produced significant reductions in blood pressure and in cardiac parasympathetic indices. During the high intensity session, ΔV1% heart rate variability index was positively correlated with blood pressure reductions. During the low intensity session, low frequency was negatively correlated with blood pressure. In conclusion, both high and low intensity RT elicited acute hypotensive effects, with a more pronounced cardiac autonomic response characterized by greater vagal withdrawal observed for the low intensity training protocol. Furthermore, changes in indices related to cardiac sympathetic modulation and greater decreases in cardiac parasympathetic modulation were associated with a greater post exercise hypotensive response.