Abstract
The present study determined metabolic and performance responses to repeated sprint exercise under hypoxia among female team-sport athletes. Fifteen female athletes (age, 20.7±0.2 years; height, 159.6±1.7 cm; body weight, 55.3±1.4 kg) performed two exercise trials under either a hypoxic [HYPO; fraction of inspired oxygen (FiO2), 14.5%] or normoxic (NOR; FiO2, 20.9%) condition. The exercise consisted of two sets of 8×6-s maximal sprint (pedaling). The average power output was not significantly different between trials for set 1 (P=0.89), but tended to be higher in the NOR trial for set 2 (P=0.05). The post-exercise blood lactate concentrations were significantly higher in the HYPO trial than that in the NOR trial (P<0.05). Exercise significantly increased serum growth hormone (GH) and cortisol concentrations (P<0.01 for both hormones), with no difference between the trials. In conclusion, repeated short-duration sprints interspaced with 30-s recovery periods in moderate hypoxia caused further increase in blood lactate compared with the same exercise under normoxic conditions among female team-sport athletes. However, exercise-induced GH and cortisol elevations or power output during exercise were not markedly different regardless of the different levels of inspired oxygen.
Key words
maximal sprint - hypoxic exercise - blood lactate concentration - female team-sport athletes