Effects of Aerobic Capacity on Intramuscular Metabolism and Oxygen Kinetics during Resistance Exercise with Blood Flow Restriction

Abstract

Blood flow restriction (BFR) remarkably enhances intramuscular energetic metabolism in resistance exercise; however, its mechanism has not been known. We hypothesized that it was associated with oxidative capacity. Therefore, we investigated intramuscular metabolic responses during low-intensity resistance exercise with BFR in track athletes. Twelve male college athletes were recruited and performed unilateral plantar-flexion (30 repetitions/minute for 2 minutes) during low-intensity exercise at 20% of one repetition maximum with BFR. Intramuscular energetic metabolism and muscle oxygenation were evaluated using ³¹P-magnetic resonance spectroscopy and near infrared spectroscopy, respectively. Subjects were divided into the two groups based on aerobic capacity. Phosphocreatine (PCr) decrease in subjects with high-aerobic capacity during BFR exercise was greater than that in subjects with low-aerobic capacity (p=0.077), without the difference in muscular oxygenation. The PCr decrease during BFR exercise was significantly correlated with peak oxygen uptake (r=0.735, p<0.01). In conclusion, the effects of low-intensity resistance exercise with BFR might be greater in subjects with higher aerobic capacity.