Abstract
PURPOSE: This study examined the effects of intermittent blood flow restriction (LI-BFR) compared to low- (LI) and high-intensity interval exercise (HI) on substrate utilization and energy expenditure (EE). METHODS: Exercise protocols consisted of 2-minute work intervals interspersed with 1-minute recovery intervals (20W), HI consisted of 5 intervals performed at a workload corresponding to 140% of ventilatory threshold intensity and LI and LI-BFR consisted of 10 intervals performed at 70% of ventilatory threshold. BFR cuffs were inflated to 80% of limb occlusion pressure during each work interval and deflated during each recovery. Following each exercise protocol subjects rested for three hours, during which excess EE and substrate utilization were measured. For all comparisons, statistical significance was set at p ≤ 0.05. RESULTS: Fat oxidation rate was significantly greater in LI-BFR (0.11 ± 0.03 g min(-1)) compared to HI (0.09 ± 0.03 g min(-1)) at 120 MIN (d = 1.13). Fat oxidation in LI-BFR (60 MIN = 0.14 ± 0.01 g·min(-1), 120 MIN = 0.11 ± 0.01 g min(-1)) was greater than LI (60 MIN = 0.08 ± 0.02 g min(-1), 120 MIN = 0.9 ± 0.02 g min(-1)). Total excess EE was greater in LI-BFR (184.0 ± 37.6 kcals) compared to HI (127.0 ± 12.0 kcals; d = 3.23) and LI (144.83 ± 35.5 kcals; d = 2.21). CONCLUSION: This study suggests that the addition of BFR to low-intensity results in increased fat oxidation following exercise as well as increased EE. The observed increased fat oxidation and EE could potentially have significant long-term effects on weight management.