Horiuchi Masahiro, Nishida Ayano, Dobashi Shohei, Koyama Katsuhiro
Division of Human Environmental Science, Mount Fuji Research Institute, Fuji-yoshida, Japan.
Graduate School of Education, University of Yamanashi, Kofu, Japan.
Front Physiol. 2022 Mar 24;13:843574. doi: 10.3389/fphys.2022.843574. eCollection 2022.
The aim of this study was to investigate the effects of either normoxic or hypoxic recovery condition on post-exercise hemodynamics after sprint interval leg cycling exercise rather than hemodynamics during exercise. The participants performed five sets of leg cycling with a maximal effort (30 s exercise for each set) with a 4-min recovery of unloaded cycling between the sets in hypoxia [fraction of inspired oxygen (FiO) = 0.145]. The load during pedaling corresponded to 7.5% of the individual's body weight at the first set, and it gradually reduced from 6.5 to 5.5%, 4.5, and 3.5% for the second to fifth sets. After exercise, the participants rested in a sitting position for 30 min under normoxia (room-air) or hypoxia. Mean arterial pressure decreased over time during recovery ( < 0.001) with no condition and interaction effects ( > 0.05). Compared to pre-exercise values, at 30 min after exercise, mean arterial pressure decreased by 5.6 ± 4.8 mmHg (mean ± standard deviation) during hypoxic recovery, and by 5.3 ± 4.6 mmHg during normoxic recovery. Peripheral arterial oxygen saturation (SpO) at all time points (5, 10, 20, and 30 min) during hypoxic recovery was lower than during normoxic recovery (all < 0.05). The area under the hyperemic curve of tissue oxygen saturation (StO) at vastus lateralis defined as reperfusion curve above the baseline values during hypoxic recovery was lower than during normoxic recovery ( < 0.05). Collectively, post-exercise hypotension after sprint interval leg cycling exercise was not affected by either normoxic or hypoxic recovery despite marked differences in SpO and StO during recovery between the two conditions.
本研究的目的是调查常氧或低氧恢复条件对短跑间歇腿部骑行运动后运动后血流动力学的影响，而非运动期间的血流动力学。参与者在低氧环境下（吸入氧分数[FiO]=0.145）进行五组腿部骑行，每组竭尽全力骑行30秒，组间进行4分钟无负荷骑行恢复。蹬踏时的负荷在第一组相当于个体体重的7.5%，从第二组到第五组逐渐从6.5%降至5.5%、4.5%和3.5%。运动后，参与者在常氧（室内空气）或低氧环境下坐位休息30分钟。恢复过程中平均动脉压随时间下降（<0.001），无条件和交互作用影响（>0.05）。与运动前值相比，运动后30分钟，低氧恢复时平均动脉压下降5.6±4.8mmHg（平均值±标准差），常氧恢复时下降5.3±4.6mmHg。低氧恢复期间所有时间点（5、10、20和30分钟）的外周动脉血氧饱和度（SpO）均低于常氧恢复期间（均<0.05）。股外侧肌组织氧饱和度（StO）充血曲线下面积（定义为低氧恢复期间高于基线值的再灌注曲线）低于常氧恢复期间（<0.05）。总体而言，短跑间歇腿部骑行运动后的运动后低血压不受常氧或低氧恢复的影响，尽管两种条件下恢复期间SpO和StO存在显著差异。
