Impact of Hypobaric Hypoxia on Repeated Sprint Performance

Abstract

PURPOSE: To investigate the impact of hypobaric hypoxia on sprint performance and metabolic recovery after repeated sprint bouts. METHODS: Six men (20±3yrs; 77±13kg; 181±12cm) performed three familiarization sprint sessions (decrease learning effects) at sea level (SL). Sprint sessions consisted of repeated high intensity exercise bouts (30 sec all-out sprint: 1min rest) on a self-propelled treadmill. Following familiarization, volunteers performed one sprint session per week at 250m, 2000m, and 3000m (random order) carrying a load (30% body mass) in a hypobaric chamber. Sprints were repeated until peak velocity decreased by 20% of that established during familiarization. Pre- and post sprint arterial oxygen saturation (SaO2), heart rate (HR), rate of perceived exertion (RPE), and blood lactate (Hla) were measured. RESULTS: There was no difference (P > 0.05) in the # of sprints completed at SL, 250m, 2000m, and 3000m (5±3, 5±2, 4±2, 4±1, respectively). Post sprint session SaO2 values were lower (P < 0.05) as altitude increased (96±2%, 250m; 90±5%, 2000m; 82±4%, 3000m). Post session HR, RPE, and blood Hla were elevated (P < 0.05) vs. pre- session values, but were not different (P > 0.05) among altitudes. CONCLUSIONS: While repeated sprint performance was not affected due to hypobaric hypoxia, post session SaO2 was reduced with each decrease in barometric pressure. It appears that the lower SaO2 values associated with the simulated altitudes tested did not alter the aerobic recovery of anaerobic pathways used during sprinting as the SaO2 values were not low enough to be a limiting factor. The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government.