Acute Effects of Blood Flow-restricted Exercise on Microcirculation, Neuromuscular Activation and Metabolite in Underweight Women.

Abstract

to either HYPER (FiO2 0.30; n=12) or NORM (FiO2 0.21; n=11) breathing condition during training in a single blinded study design. VO2max, OXPHOS capacity in permeabilized fibers and in isolated mitochondria, and 20 min cycle performance were tested pre and post intervention. RESULTS: Over the intervention change in VO2max (HYPER 1.1±3.8%, NORM 0.0±3.7%; p = 0.55, ES= 0.08), mass-specific mitochondrial respiration (HYPER 27.3±46.0 %, NORM 16.5±49.1%; p= 0.21, ES= -0.06); intrinsic mitochondrial respiration (HYPER 26.1±80.1%, NORM 15.9±73.3%; p = 0.66, ES= 0.69) and mean power output during 20 min trial (HYPER 6.0±3.7%, NORM 2.4±5.0%; p = 0.073, ES= 0.32) did not statistically significantly differ between the groups. CONCLUSIONS: These data showed that 6 weeks hyperoxic-supplemented high-intensity interval-training on a cycle ergometer was not superior to conventional training at sea level in improving VO2max, intrinsic and mass-specific mitochondrial respiration and cycle performance in already trained cyclists. Therefore, despite the small meaningful positive effect in cycling performance that might be relevant in sport, considering the cost/benefit of performing hyperoxic-supplemented HIIT, it is questionable whether this strategy is worthwhile in maximizing endurance performance in already trained cyclists.