Dufour Stéphane P, Ponsot Elodie, Zoll Joffrey, Doutreleau Stéphane, Lonsdorfer-Wolf Evelyne, Geny Bernard, Lampert Eliane, Flück Martin, Hoppeler Hans, Billat Véronique, Mettauer Bertrand, Richard Ruddy, Lonsdorfer Jean
Département de Physiologie et des Explorations Fonctionnelles, Hôpital Civil, and Faculté de Médicine, Institut de Physiologie, Unité Propre de Recherche de l'Enseignement Supérieur Equipe d'Accueil, 3072 Strasbourg, France.
J Appl Physiol (1985). 2006 Apr;100(4):1238-48. doi: 10.1152/japplphysiol.00742.2005.
This study investigates whether a 6-wk intermittent hypoxia training (IHT), designed to avoid reductions in training loads and intensities, improves the endurance performance capacity of competitive distance runners. Eighteen athletes were randomly assigned to train in normoxia [Nor group; n = 9; maximal oxygen uptake (VO2 max) = 61.5 +/- 1.1 ml x kg(-1) x min(-1)] or intermittently in hypoxia (Hyp group; n = 9; VO2 max = 64.2 +/- 1.2 ml x kg(-1) x min(-1)). Into their usual normoxic training schedule, athletes included two weekly high-intensity (second ventilatory threshold) and moderate-duration (24-40 min) training sessions, performed either in normoxia [inspired O2 fraction (FiO2) = 20.9%] or in normobaric hypoxia (FiO2) = 14.5%). Before and after training, all athletes realized 1) a normoxic and hypoxic incremental test to determine VO2 max and ventilatory thresholds (first and second ventilatory threshold), and 2) an all-out test at the pretraining minimal velocity eliciting VO2 max to determine their time to exhaustion (T(lim)) and the parameters of O2 uptake (VO2) kinetics. Only the Hyp group significantly improved VO2 max (+5% at both FiO2, P < 0.05), without changes in blood O2-carrying capacity. Moreover, T(lim) lengthened in the Hyp group only (+35%, P < 0.001), without significant modifications of VO2 kinetics. Despite similar training load, the Nor group displayed no such improvements, with unchanged VO2 max (+1%, nonsignificant), T(lim) (+10%, nonsignificant), and VO2 kinetics. In addition, T(lim) improvements in the Hyp group were not correlated with concomitant modifications of other parameters, including VO2 max or VO2 kinetics. The present IHT model, involving specific high-intensity and moderate-duration hypoxic sessions, may potentialize the metabolic stimuli of training in already trained athletes and elicit peripheral muscle adaptations, resulting in increased endurance performance capacity.
本研究调查了一种旨在避免训练负荷和强度降低的为期6周的间歇性低氧训练（IHT）是否能提高竞技长跑运动员的耐力表现能力。18名运动员被随机分配到常氧环境下训练[常氧组；n = 9；最大摄氧量（VO2 max）= 61.5±1.1 ml·kg⁻¹·min⁻¹]或间歇性低氧环境下训练（低氧组；n = 9；VO2 max = 64.2±1.2 ml·kg⁻¹·min⁻¹）。在他们常规的常氧训练计划中，运动员每周包括两次高强度（第二通气阈值）和中等时长（24 - 40分钟）的训练课程，这些课程在常氧环境下[吸入氧分数（FiO2）= 20.9%]或常压低氧环境下（FiO2 = 14.5%）进行。在训练前后，所有运动员都进行了1）常氧和低氧递增测试以确定VO2 max和通气阈值（第一和第二通气阈值），以及2）在训练前能引出VO2 max的最低速度下进行全力测试，以确定他们的疲劳时间（T(lim)）和摄氧量（VO2）动力学参数。只有低氧组显著提高了VO2 max（在两种FiO2条件下均提高了5%，P < 0.05），而血液携氧能力没有变化。此外，只有低氧组的T(lim)延长了（+35%，P < 0.001），VO2动力学没有显著改变。尽管训练负荷相似，但常氧组没有出现这样的改善，VO2 max（+1%，无显著性差异）、T(lim)（+10%，无显著性差异）和VO2动力学均未改变。此外，低氧组T(lim)的改善与其他参数（包括VO2 max或VO2动力学）的相应变化无关。目前的IHT模型，包括特定的高强度和中等时长的低氧训练课程，可能会增强对已经训练有素的运动员的训练代谢刺激，并引发外周肌肉适应，从而提高耐力表现能力。
