School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Australia.
Western Australian Institute of Sport, Mt Claremont, Australia.
Eur J Sport Sci. 2023 Jul;23(7):1175-1185. doi: 10.1080/17461391.2022.2085631. Epub 2022 Sep 12.
The aim of this study was to investigate acute performance and physiological responses to the manipulation of exercise-to-rest ratio (E:R) during repeated-sprint hypoxic training (RSH) in hot conditions. Twelve male team-sport players completed two experimental sessions at a simulated altitude of ∼3000 m (FO 0.144), air temperature of 40°C and relative humidity of 50%. Exercise involved either 3 × 5 × 10-s (E:R) or 3 × 10 × 5-s (E:R) maximal cycling sprints interspersed with active recoveries at 120W (20-s between sprints, 2.5 and 5-min between sets for E:R and E:R respectively). Sessions were matched for overall sprint and total session duration (47.5-min). Peak and mean power output, and total work were greater in E:R than E:R ( < 0.05). Peak core temperature was significantly higher in E:R than E:R (38.44 ± 0.33 vs. 38.20 ± 0.35°C, = 0.028). Muscle deoxygenation magnitude during sprints was greater in E:R (28.2 ± 1.6 vs. 22.4 ± 4.6%, < 0.001), while muscle reoxygenation did not differ between conditions ( > 0.05). These results indicate E:R increased mechanical power output and core temperature compared to E:R. Both protocols had different effects on measures of muscle oxygenation, with E:R generating greater muscle oxygen extraction and E:R producing more muscle oxygenation flux, which are both important signals for peripheral adaptation. We conclude that the E:R manipulation during RSH in the heat might be used to target different physiological and performance outcomes, with these findings forming a strong base for future mechanistic investigation. During a typical repeated-sprint training session conducted in hot and hypoxic conditions, an exercise-to-rest ratio of 1:4 during sprint efforts displayed an increased mechanical power output compared to an exercise-to-rest ratio of 1:2. This represents a potentially useful increase in training stimulus.An exercise-to-rest ratio of 1:2 generated greater muscle oxygen extraction, while an exercise-to-rest ratio of 1:4 resulted in more muscle oxygenation flux and a higher core temperature, indicating key markers of environment-related physiological strain were varied between conditions.Exercise-to-rest ratio manipulation may be used to target different physiological and performance outcomes when prescribing repeated-sprint training in hot and hypoxic conditions.
本研究旨在探讨在模拟海拔约 3000 米（FO0.144）、环境温度 40°C 和相对湿度 50%的热环境下，改变运动与恢复比例（E:R）对重复冲刺缺氧训练（RSH）中急性表现和生理反应的影响。12 名男性团队运动运动员在两个实验中完成了两个实验，每次实验均在模拟海拔约 3000 米（FO0.144）、环境温度 40°C 和相对湿度 50%的条件下进行。运动包括 3×5×10 秒（E:R）或 3×10×5 秒（E:R）的最大自行车冲刺，每次冲刺之间穿插主动恢复，功率为 120W（每次冲刺之间 20 秒，每次冲刺之间 2.5 分钟，每次冲刺之间 5 分钟）。每个阶段的总冲刺和总训练时间均相同（47.5 分钟）。E:R 的峰值和平均功率输出以及总工作量均大于 E:R（<0.05）。E:R 的核心温度明显高于 E:R（38.44±0.33 对 38.20±0.35°C，=0.028）。E:R 的冲刺过程中的肌肉去氧程度大于 E:R（28.2±1.6 对 22.4±4.6%，<0.001），而两种条件下肌肉再氧化程度无差异（>0.05）。这些结果表明，与 E:R 相比，E:R 增加了机械功率输出和核心温度。两种方案都对肌肉氧合的测量值有不同的影响，E:R 产生更大的肌肉氧提取，E:R 产生更多的肌肉氧合流量，这两者都是外周适应的重要信号。我们得出的结论是，在热环境下进行 RSH 时，E:R 的改变可能会针对不同的生理和表现结果，这些发现为未来的机制研究奠定了坚实的基础。在典型的热和低氧条件下进行的重复冲刺训练中，冲刺期间的运动与休息比例为 1:4 与运动与休息比例为 1:2 相比，机械功率输出增加。这代表了一种潜在的有用的训练刺激增加。运动与休息比例为 1:2 产生更大的肌肉氧提取，而运动与休息比例为 1:4 导致更多的肌肉氧合流量和更高的核心温度，这表明环境相关生理压力的关键指标在不同条件下有所不同。在热和低氧条件下进行重复冲刺训练时，运动与休息比例的改变可能会针对不同的生理和表现结果。
