Hemodynamic responses and energy expenditure during blood flow restriction exercise in obese population.

Abstract

The study investigated the acute effects of different initial restrictive pressures (IRP; tightness of cuffs before inflation with air) on heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), rating of perceived exertion (RPE), respiratory exchange ratio (RER) and energy expenditure (EE) during constant-load upright cycling. In a within subject study design, 34 obese men (age=24·3, n=18) and women (age=23·1, n=16) completed three cycling sessions (two blood flow restriction and one control sessions). The cycling exercise was performed with an external load of 1kp at 50rpm for 20min with 1-min rest after the 10th-min. The blood flow restriction (BFR) cuffs were placed on the thigh of both legs during BFR sessions and IRP and IRP of ~40 or ~60mmHg were applied in random order. There were significant condition×time interactions for HR, SBP, RPE and RER and time×gender interactions for HR and SBP. There were also significant condition and time main effects for HR, SBP, RPE and RER (P<0·01) and a significant condition effect for EE (P<0·05). The intensity of exercise with BFR was higher and affected by IRP, but the subjects perceived the effort as 'light'. Low-intensity cycling with BFR shows potential to reduce the time requirement per session to elicit greater EE while placing greater demands on the circulatory system.