Effect of Repeated-Sprint Training in Hypoxia in Female National-Level Rugby Union Players

The aim of this study was to investigate the effects of repeated-sprint training in hypoxia (RSH) versus in normoxia (RSN) in female national-level rugby union players. In a randomized, controlled, and crossover study, 8 female rugby union players performed 5 sessions of repeated sprints either in normobaric hypoxia (RSH, simulated altitude: 3000 m; FiO2 = 14.5%) or in normoxia (RSN, terrestrial altitude: 165 m; FiO2 = 20.5%). Before (Pre) and after (Post) training, repeated-sprint ability (6 × 10-s "all-out" sprints and 20-s recovery) was evaluated on a cycle ergometer. From Pre to Post, peak power output was improved in RSH (602 [98] vs 704 [92] W; P = .007) but not in RSN (661 [91] vs 673 [76] W; P = .560). Similarly, mean power output was enhanced in RSH (445 [63] vs 532 [51] W; P = .013) but not in RSN (499 [88] vs 509 [63] W; P = .557). Sprint decrement did not change in either RSH (24.5 [8.9] vs. 24.0% [5.7%]; P = .819) or RSN (22.7 [5.9] vs 24.3% [4.8%]; P = .336). As few as 5 sessions of RSH were beneficial for improving peak and mean power outputs during repeated-sprint exercise in female national-level rugby union players compared with the same training in normoxia.