Effect of Blood Flow Restricted Cycle Training on Oxygen uptake kinetics during Exercise

Abstract

A number of studies have illustrated that blood flow restricted (BFR) resistance training increasing muscle function even when low-intensity training is utilized. Recently BFR has also applied to aerobic training; however less is known about the effect of aerobic training with BFR on the oxygen uptake (VO2) kinetic responses during exercise with or without BFR. PURPOSE: To elucidate the effects of 8-weeks cycle training with BFR on VO2 kinetics at the onset of constant-load cycle exercise with or without BFR. METHODS: Eighteen healthy subjects were randomly assigned to BFR (n = 9; 22±5 yrs) or no BFR group serving as the control (CON; n = 9; 21±2 yrs). Both groups trained for 30 minutes, 3 days/week for 8 weeks. BFR was performed for 5 minutes every 10 minutes by applying cuffs to the upper thighs. Breath-by-breath VO2 was measured during the performance of 5-min moderate intensity (below the lactate threshold) or 6-min heavy intensity exercise (above the lactate threshold) without BFR at Pre-, 4 weeks after (Mid-), and Post-training. At Post, we also measured VO2 kinetics during exercise with BFR (Post+BFR). Two-way repeated ANOVAs were used (BFR vs CON and Pre vs Mid vs Post vs Post+BFR) with significance accepted as p<0.05; and Tukey’s post hoc tests utilized as needed. RESULTS: Although time constant (τ) of VO2 kinetics at the fast component during moderate exercise fitted the exponential model was significantly faster in Mid and Post than that of Pre (26.8 to 16.3 and 15.5 s and 27.5 to 22.1 and 18.5 s in BFR and CON, p<0.05, respectively), significant group-by-time interaction was not detected. The amplitude of the VO2 slow component during heavy exercise significantly decreased in Mid and Post than that of Pre (281 to 103 and 128 mL/min and 300 to 154 and 160 mL/min in BFR and CON, p<0.05, respectively), while a significant group-by-time interaction was not detected. Both τ of VO2 kinetics during moderate exercise and the amplitude of the VO2 slow component during heavy exercise significantly increased from Post to Post+BFR (19.1 and 28.0 s, and 266 and 256 mL/min in BFR and CON, p<0.05, respectively); however significant group-by-time interactions were not detected either. CONCLUSION: Appling the BFR to eight-weeks cycle training showed no further change in VO2 kinetics at the onset of exercise. Supported by KAKENHI (23700788)