No additional benefit of repeat-sprint training in hypoxia than in normoxia on sea-level repeat-sprint ability

To assess the impact of ‘top-up’ normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability,thirty team sport athletes were randomly split into three groups,which were matched in running repeat-sprint ability (rsa),cycling rsa and 20 m shuttle run performance. two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks,in either normoxia (norm) or hypoxia (hyp),while a third group acted as a control (con). in the post-training cycling rsa test,both norm (13.6%; p = 0.0001,and 8.6%; p = 0.001) and hyp (10.3%; p = 0.007,and 4.7%; p = 0.046) signif-icantly improved overall mean and peak power output,respec-tively,whereas con did not change (1.4%; p = 0.528,and -1.1%; p = 0.571,respectively); with only norm demonstrating a moderate effect for improved mean and peak power output compared to con. running rsa demonstrated no significant between group differences; however,the mean sprint times improved significantly from pre- to post-training for con (1.1%),norm (1.8%),and hyp (2.3%). finally,there were no group differences in 20 m shuttle run performance. in conclu-sion,‘top-up’ training improved performance in a task-specific activity (i.e. cycling); however,there was no additional benefit of conducting this ‘top-up’ training in hypoxia,since cycle rsa improved similarly in both hyp and norm conditions. re-gardless,the ‘top-up’ training had no significant impact on running rsa,therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. © journal of sports science and medicine.