Effects of repeated-sprint hypoxic training on physical fitness of active adults

Abstract

Due to the time is, commonly, a barrier to exercise, the scientific community has paid attention to a new model of training. Repeated-sprint hypoxic training is now considered an effective time-efficient method for improving physical performance in different sport modalities. However, few researchers have studied the effect of this strategy in healthy untrained or moderately trained individuals. Depending of the prior fitness status, different findings may be obtained. Therefore, this study determined the effects of 4 weeks of repeated-sprint in hypoxia on cardiorespiratory fitness and anaerobic capacity in healthy men. Twenty-four physically active males (were randomly assigned to repeated-sprint in normoxia (n=8; 0.20 FiO2), in hypoxia (n=8; 0.14 FiO2) or a control group (n=8). Participants of both exercise groups developed eight training sessions consisted of 2 sets of 5 all-out cycling sprints of 10 s with a recovery of 20 s between sprints and 10 min between sets. Repeated sprint ability, vertical jump performance and estimated maximal oxygen consumption were tested at baseline, 7 days and 2 weeks after the last session. Seven days after the last sessions, significant differences (p<0.05) between normoxia (+7.8%; p<0.001; ES=1.66) and hypoxia groups (+9.9%; p=0.000; ES=1.42) compared with control group were found in estimated maximal oxygen consumption. In the hypoxia group, the number of sprints to exhaustion (7 days Post +55.6%; ES=1.40; 2 weeks Post +10.0%; ES=1.80) improved with a large effect size at 7 days and 2 weeks after the last sessions compared with baseline. Eight sessions of repeated-sprint training in hypoxia conditions could produce improvements and delayed effects on anaerobic capacity.