Introduction: Recently, many studies have reported that high-intensity or sprint interval training can improve not only anaerobic (glycolytic) metabolism but also aerobic (oxidative) metabolism and that these metabolic adaptations cause improvements in exercise performance. Also, training under hypoxic conditions has been primarily performed for the purpose of improving O2 transport system, i.e. maximal aerobic power (VO2max). However, several studies reported that maximal accumulated O2 deficit (MAOD) and buffering capacity increased after altitude training (Mizuno et al. 1990, Ogita 2006), and the possibility that the hypoxic training may improve effectively anaerobic energy releasing system was suggested. Therefore, the present study aimed to examine whether very high-intensity, low-volume, sprint interval training (SIT) under hypobaric hypoxic conditions improve more effectively metabolic capacity and high-intensity exercise performance. Methods: Fourteen healthy male students (22±1 yrs) were matched for baseline measurements into two groups and then randomized to normobaric normoxic training group (N, n=7) and hypobaric hypoxic training group (H, n=7). The subjects had a SIT using a bicycle ergometer, which consisted of five 5 s bouts at an intensity which cause exhaustion in around 10 s (~300% VO2max) with a 10s rest between each bout. SIT was conducted twice/day, 5 days/week, for 4 weeks, and H performed it under hypobaric hypoxic conditions corresponding to 4000 m above sea level. Before and after training, VO2max, and MAOD, and intermittent exercise performance (IE; ten 5 s bout with a 20 s rest) were determined. Results: After the 4 weeks of training, VO2max significantly increased in N (P<0.05), but not in H. On the other hand, a significant increase was found in MAOD (P<0.01), total work in IE (P<0.05) in both groups. Furthermore, peak power output in IE increased significantly only in H (P<0.05). Discussion/Conclusion: These findings suggest that the SIT used in this experiment could induce a large improvement of MAOD and high-intensity exercise performance in both conditions but that the SIT under hypobaric hypoxic conditions might be more beneficial to improve maximal power output.
© Copyright 2016 21st Annual Congress of the European College of Sport Science (ECSS), Vienna, 6. -9. July 2016. Julkaistu Tekijä University of Vienna. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator