Effects of Active Preconditioning With Local and Systemic Hypoxia on Submaximal Cycling.

PURPOSE The authors compared the effects of active preconditioning with local and systemic hypoxia during submaximal cycling. METHODS On separate visits, 14 active participants completed 4 trials. Each visit was composed of 1 preconditioning phase followed, after 40 minutes of rest, by 3 × 6-minute cycling bouts (intensity = 85% of critical power; rest = 6 min). The preconditioning phase consisted of 4 × 5-minute cycling bouts at 1.5 W·kg-1 (rest = 5 min) in 4 conditions: control (no occlusion and normoxia), blood flow restriction (60% of total occlusion), HYP (systemic hypoxia; inspired fraction of oxygen = 13.6%), and blood flow restriction + HYP (local and systemic hypoxia combined). RESULTS During the preconditioning phase, there were main effects of both systemic (all P .105). CONCLUSION Local and systemic hypoxic stimuli, or a combination of both, during active preconditioning did not improve physiological responses such as cycling efficiency during subsequent submaximal cycling.