Hemodynamic responses to an isometric handgrip training protocol

Abstract

Background: In the past, isometric exercises were proscribed for heart disease. However, recent evidence suggests that an isometric handgrip training (IHT) protocol - four sets of two minutes at 30% of maximum strength - produces favorable effects on the autonomic modulation and reduces resting systolic (SBP) and diastolic (DBP) blood pressure. Objective: Aiming at obtaining support for broad clinical applicability, we quantified the main hemodynamic responses during an IHT session in patients from a supervised physical exercise program. Methods: Forty-one patients (36 men) underwent the IHT with measurements of heart rate (HR) and BP before, during each of the two series performed with the left arm and one minute after completion. Measurements were obtained by an electrocardiogram signal in a digital Tango + oscillometric tensiometer, previously validated for physical exercise conditions. Results: The IHT was appropriately carried out, with no clinical adverse reactions. There was a small increase in SBP and DBP levels, respectively, of 16 and 7 mmHg (p <0.05) and an even smaller increase in HR - 3 bpm - (p <0.05) when we compared the data obtained at 80 seconds of the last series with the pre-exercise ones. HR, SBP and DBP values had almost returned to baseline one minute post-exercise. Conclusions: IHT was well tolerated by patients undergoing exercise programs, resulting in a transient and modest hemodynamic effect, without inducing rapid cardiac vagal inactivation, characteristic of dynamic and short exercises.