The Effect Of Isometric Hand-grip Exercise With Blood Flow Restriction On Hemodynamic Responses

Abstract

Several studies have examined the effect of isometric handgrip exercise at submaximal intensities on cardiovascular system. However, few studies have focused on hemodynamic responses and muscle fatigue while exercising with blood flow restriction (BFR). PURPOSE: This crossover study examined the hemodynamic responses and muscle fatigue of an isometric, low intensity hand grip exercise protocol performed under blood flow restriction. METHODS: Twenty-four healthy adult volunteers (12 women and 12 men, age: 23.3 ± 1.9, BMI: 24.9 ± 6.2 kg/m2) performed 4 sessions of isometric hand grip exercise at 30% of maximal isometric strength using a grip dynamometer. Each session lasted 2 min and was performed in two conditions, without (control-C) and with blood flow restriction- BFR on different days. Blood flow restriction was achieved by applying a blood flow restriction cuff at a pressure of 140 mmHg. Hemodynamic responses (systolic and diastolic arterial blood pressure-SBP and DBP, heart rate-HR, and oxygen saturation- OS SpO2) and muscle fatigue (maximal isometric grip strength- IMVC and Borg scale) were assessed before, at the end of each exercise session, and 15 minutes after exercise performed under the two different conditions. Two-way ANOVA with repeated measures was used for statistics and data are given as mean(SD). RESULTS: Outcomes measures mean score (SD) for each time point of measurement in the two exercise conditions.* Between groups significant comparisons in the post hoc testing. BFRT: Blood Flow Restriction Training, Control: Conduction of exercise with no blood restriction, HR: Heart Rate, SBP: Systolic Blood Pressure, DBP: Diastolic Blood Pressure, OS: Oxygen Saturation, IMVC: Isometric Maximal Voluntary Contraction CONCLUSIONS: A submaximal isometric hand grip exercise does not induce significant hemodynamic changes, though it causes a more intense feeling of fatigue.