Inness M W H, Billaut François, Aughey Robert J
Inst of Sport, Exercise and Active Living, Victoria University, Melbourne, VIC, Australia.
Int J Sports Physiol Perform. 2016 Jan;11(1):15-21. doi: 10.1123/ijspp.2014-0246. Epub 2015 Apr 7.
To determine the time course for physical-capacity adaptations to intermittent hypoxic training (IHT) in team-sport athletes and the time course for benefits remaining after IHT.
A pre-post parallel-groups design was employed, with 21 Australian footballers assigned to IHT (n = 10) or control (CON; n = 11) matched for training load. IHT performed eleven 40-min bike sessions at 2500-m altitude over 4 wk. Yo-Yo Intermittent Recovery Test level 2 (Yo-Yo IR2) was performed before; after 3, 6, and 11 IHT sessions; and 30 and 44 d after IHT. Repeated time trials (2- and 1-km TTs, with 5 min rest) were performed before, after, and 3 wk after IHT. Hemoglobin mass (Hb(mass)) was measured in IHT before and after 3, 6, 9, and 11 sessions.
Baseline Yo-Yo IR2 was similar between groups. After 6 sessions, the change in Yo-Yo IR2 in IHT was very likely higher than CON (27% greater change, effect size 0.77, 90% confidence limits 0.20;1.33) and likely higher 1 d after IHT (23%, 0.68, 0.05;1.30). The IHT group's change remained likely higher than CON 30 d after IHT (24%, 0.72, 0.12;1.33) but was not meaningfully different 44 d after (12%, 0.36, -0.24;0.97). The change in 2-km TT performance between groups was not different throughout. For 1-km TT, CON improved more after IHT, but IHT maintained performance better after 3 wk. Hb(mass) was higher after IHT (2.7%, 0.40, -0.40;1.19).
Short-duration IHT increased Yo-Yo IR2 compared with training-load-matched controls in 2 wk. An additional 2 wk of IHT provided no further benefit. These changes remained until at least 30 d posttraining. IHT also protected improvement in 1-km TT.
确定团队运动运动员对间歇性低氧训练（IHT）的身体能力适应的时间进程以及IHT后益处持续的时间进程。
采用前后平行组设计，将21名澳大利亚足球运动员按训练负荷匹配分为IHT组（n = 10）或对照组（CON；n = 11）。IHT组在4周内于海拔2500米处进行了11次40分钟的自行车训练。在训练前、3次、6次和11次IHT训练后以及IHT训练后30天和44天进行Yo-Yo间歇性恢复测试2级（Yo-Yo IR2）。在训练前、训练后以及训练后3周进行重复计时赛（2公里和1公里计时赛，休息5分钟）。在IHT训练前、3次、6次、9次和11次训练后测量血红蛋白质量（Hb(mass)）。
两组的基线Yo-Yo IR2相似。6次训练后，IHT组的Yo-Yo IR2变化极有可能高于对照组（变化高27%，效应量0.77，90%置信区间0.20；1.33），且在IHT训练后1天也可能更高（23%，0.68，0.05；1.30）。IHT组的变化在IHT训练后30天仍可能高于对照组（24%，0.72，0.12；1.33），但在44天后无显著差异（12%，0.36， -0.24；0.97）。两组之间2公里计时赛成绩的变化在整个过程中无差异。对于1公里计时赛，对照组在IHT训练后提高更多，但IHT组在3周后成绩保持得更好。IHT训练后Hb(mass)更高（2.7%，0.40， -0.40；1.19）。
与训练负荷匹配的对照组相比，短期IHT在2周内增加了Yo-Yo IR2。额外2周的IHT没有带来进一步的益处。这些变化至少持续到训练后30天。IHT还保护了1公里计时赛成绩的提高。
