Repeated Sprint Training in Hypoxia Improves Repeated Sprint Ability to Exhaustion Similarly in Active Males and Females.

ABSTRACT

PURPOSE: The aim of this study was to compare the physiological adaptations of males and females to repeated sprint training in hypoxia (RSH). METHODS: Active males and females completed 7 wk of repeated sprint training in normoxia (RSN; F i O 2 = 0.209, males n = 11, females n = 8) or RSH (F i O 2 = 0.146, males n = 12, females n = 10). Before (Pre-) and after (Post-) training, a repeated sprint ability (RSA) test was performed (10-s cycle sprints with 20-s recovery between sprints, until exhaustion), and aerobic and anaerobic qualities were evaluated in normoxia. RESULTS: The number of sprints during RSA increased after training in HYP from 11 to 21 in males and from 8 to 14 in females ( P < 0.001, 95% confidence interval = 5-11), without significant changes after RSN (10 vs 14 and 8 vs 10 in males and females, respectively). No improvements in mean or peak power output were found in either group. Total work during RSA improved after training in all groups (+9 ± 2 kJ, P < 0.001). Tissue saturation index during the repeated sprints was higher in females than males (+10% ± 2%, P < 0.001). The difference in tissue saturation index between the recovery and sprint phases remained unchanged after training. O 2 peak during an incremental exercise test increased in all groups (+3 ± 1 mL·kg -1 ·min -1 , P = 0.039). Mean power output during a Wingate test also increased in both males and females in RSN and RSH (+0.38 ± 0.18 W·kg -1 , P = 0.036). No changes were observed in hematological parameters after training. CONCLUSIONS: Seven weeks of RSH further increased the number of repeated sprints performed to exhaustion compared with RSN in females, in the same order of magnitude as in males.