School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Perth, Western Australia, Australia.
Hong Kong Sports Institute, Scientific Conditioning Centre, Elite Training Science and Technology Division, Hong Kong, Hong Kong.
Eur J Sport Sci. 2024 Aug;24(8):1045-1055. doi: 10.1002/ejsc.12146. Epub 2024 Jun 14.
We examine the impact of the acute manipulation of oxygen availability during discrete phases (active and passive) of a repeated-sprint cycling protocol on performance, physiological, and perceptual responses. On separate days, twelve trained males completed four sets of five 5-s 'all out' cycle sprints (25-s inter-sprint recovery and 5-min interset rest) in four randomized conditions: normobaric hypoxia (inspired oxygen fraction of 12.9%) applied continuously (C-HYP), intermittently during only the sets of sprints (I-HYP) or between-sets recovery periods (I-HYP), or not at all (C-NOR). Peak and mean power output, peripheral oxygen saturation, heart rate, blood lactate concentration, exercise-related sensations, and vastus lateralis muscle oxygenation using near-infrared spectroscopy were assessed. Peak and mean power output was ∼4%-5% lower for C-HYP compared to C-NOR (P ≤ 0.050) and I-HYP (P ≤ 0.027). Peripheral oxygen saturation was lower during C-HYP and I-HYP compared with C-NOR and I-HYP during sets of sprints (∼83-85 vs. ∼95%-97%; P < 0.001), while lower values were obtained for C-HYP and I-HYP than C-NOR and I-HYP during between-sets rest period (∼84-85 vs. ∼96%; P < 0.001). Difficulty in breathing was ∼21% higher for C-HYP than C-NOR (P = 0.050). Ratings of perceived exertion (P = 0.435), limb discomfort (P = 0.416), heart rate (P = 0.605), blood lactate concentration (P = 0.976), and muscle oxygenation-derived variables (P = 0.056 to 0.605) did not differ between conditions. In conclusion, the method of hypoxic exposure application (continuous vs. intermittent) affects mechanical performance, while internal demands remained essentially comparable during repeated cycle sprints.
我们研究了在重复冲刺自行车方案的主动和被动阶段（分别是积极和被动阶段）期间，急性氧可用性操纵对性能、生理和感知反应的影响。在不同的日子里，十二名训练有素的男性在四种随机条件下完成了四组五次 5 秒的“全力”自行车冲刺（25 秒冲刺间隔恢复和 5 分钟组间休息）：持续应用常压低氧（吸入氧分数为 12.9%）（C-HYP）、仅在冲刺组间间歇性应用（I-HYP）或在组间恢复期间应用（I-HYP）、或根本不应用（C-NOR）。评估了峰值和平均功率输出、外周血氧饱和度、心率、血乳酸浓度、与运动相关的感觉以及使用近红外光谱的股外侧肌氧合作用。与 C-NOR（P≤0.050）和 I-HYP（P≤0.027）相比，C-HYP 时的峰值和平均功率输出降低了约 4%-5%。与 C-NOR 和 I-HYP 相比，C-HYP 和 I-HYP 时外周血氧饱和度较低，冲刺组间（分别为 83-85%对 95%-97%；P<0.001），而在组间休息期间，C-HYP 和 I-HYP 时的数值比 C-NOR 和 I-HYP 时更低（分别为 84-85%对 96%；P<0.001）。与 C-NOR 相比，C-HYP 时呼吸难度高约 21%（P=0.050）。感觉用力程度（P=0.435）、肢体不适（P=0.416）、心率（P=0.605）、血乳酸浓度（P=0.976）和肌肉氧合衍生变量（P=0.056 至 0.605）在不同条件之间没有差异。总之，低氧暴露应用（连续与间歇）的方法会影响机械性能，而在重复的自行车冲刺过程中，内部需求基本保持不变。
