Cyr-Kirk Shannon, Billaut François
Département de kinésiologie, Université Laval, Quebec City, QC, Canada.
Front Sports Act Living. 2022 Mar 11;4:817280. doi: 10.3389/fspor.2022.817280. eCollection 2022.
This study investigated the impact of hyperoxic gas breathing (HYP) on repeated-sprint ability (RSA) and on the associated training load (TL). Thirteen team- and racquet-sport athletes performed 6-s all-out sprints with 24-s recovery until exhaustion (power decrement ≥ 15% for two consecutive sprints) under normoxic (NOR: FO 0.21) and hyperoxic (HYP: FO 0.40) conditions in a randomized, single-blind and crossover design. The following variables were recorded throughout the tests: mechanical indices, arterial O saturation (SO), oxygenation of the vastus lateralis muscle with near-infrared spectroscopy, and electromyographic activity of the vastus lateralis, rectus femoris, and gastrocnemius lateralis muscles. Session TL (work × rate of perceived exertion) and neuromuscular efficiency (work/EMG [Electromyography]) were calculated. Compared with NOR, HYP increased SO (2.7 ± 0.8%, Cohen's effect size ES 0.55), the number of sprints (14.5 ± 8.6%, ES 0.28), the total mechanical work (13.6 ± 6.8%, ES 0.30), and the session TL (19.4 ± 7.0%, ES 0.33). Concomitantly, HYP increased the amplitude of muscle oxygenation changes during sprints (25.2 ± 11.7%, ES 0.36) and recovery periods (26.1 ± 11.4%, ES 0.37), as well as muscle recruitment (9.9 ± 12.1%, ES 0.74), and neuromuscular efficiency (6.9 ± 9.0%, ES 0.24). It was concluded that breathing a hyperoxic mixture enriched to 40% O improves the total work performed and the associated training load during an open-loop RSA session in trained athletes. This ergogenic impact may be mediated by metabolic and neuromuscular alterations.
本研究调查了高氧气体呼吸（HYP）对重复冲刺能力（RSA）以及相关训练负荷（TL）的影响。13名团队和球拍类运动运动员在常氧（NOR：FIO₂ 0.21）和高氧（HYP：FIO₂ 0.40）条件下，采用随机、单盲和交叉设计进行6秒全力冲刺，每次冲刺后恢复24秒，直至力竭（连续两次冲刺功率下降≥15%）。在整个测试过程中记录以下变量：力学指标、动脉血氧饱和度（SO）、通过近红外光谱法测量的股外侧肌氧合情况，以及股外侧肌、股直肌和腓肠肌外侧头的肌电图活动。计算每次训练的TL（工作量×主观用力程度）和神经肌肉效率（工作量/肌电图[EMG]）。与NOR相比，HYP使SO升高（2.7±0.8%，科恩效应量ES 0.55）、冲刺次数增加（14.5±8.6%，ES 0.28）、总机械功增加（13.6±6.8%，ES 0.30）以及训练TL增加（19.4±7.0%，ES 0.33）。同时，HYP使冲刺期间（25.2±11.7%，ES 0.36）和恢复期（26.1±11.4%，ES 0.37）的肌肉氧合变化幅度增加，以及肌肉募集增加（9.9±12.1%，ES 0.74）和神经肌肉效率增加（6.9±9.0%，ES 0.24）。研究得出结论，呼吸含40%氧气的高氧混合气可改善训练有素的运动员在开环RSA训练期间的总工作量和相关训练负荷。这种促力作用可能由代谢和神经肌肉改变介导。
