Ulrich Silvia, Hasler Elisabeth D, Müller-Mottet Séverine, Keusch Stephan, Furian Michael, Latshang Tsogyal D, Schneider Simon, Saxer Stéphanie, Bloch Konrad E
Pulmonary Clinic, University Hospital Zurich, Zurich, Switzerland.
Respiration. 2017;93(2):90-98. doi: 10.1159/000453620. Epub 2017 Jan 10.
The impact of hyperoxia on exercise limitation is still incompletely understood.
We investigated to which extent breathing hyperoxia enhances the exercise performance of healthy subjects and which physiologic mechanisms are involved.
A total of 32 healthy volunteers (43 ± 15 years, 12 women) performed 4 bicycle exercise tests to exhaustion with ramp and constant-load protocols (at 75% of the maximal workload [Wmax] on FiO2 0.21) on separate occasions while breathing ambient (FiO2 0.21) or oxygen-enriched air (FiO2 0.50) in a random, blinded order. Workload, endurance, gas exchange, pulse oximetry (SpO2), and cerebral (CTO) and quadriceps muscle tissue oxygenation (QMTO) were measured.
During the final 15 s of ramp exercising with FiO2 0.50, Wmax (mean ± SD 270 ± 80 W), SpO2 (99 ± 1%), and CTO (67 ± 9%) were higher and the Borg CR10 Scale dyspnea score was lower (4.8 ± 2.2) than the corresponding values with FiO2 0.21 (Wmax 257 ± 76 W, SpO2 96 ± 3%, CTO 61 ± 9%, and Borg CR10 Scale dyspnea score 5.7 ± 2.6, p < 0.05, all comparisons). In constant-load exercising with FiO2 0.50, endurance was longer than with FiO2 0.21 (16 min 22 s ± 7 min 39 s vs. 10 min 47 s ± 5 min 58 s). With FiO2 0.50, SpO2 (99 ± 0%) and QMTO (69 ± 8%) were higher than the corresponding isotime values to end-exercise with FiO2 0.21 (SpO2 96 ± 4%, QMTO 66 ± 9%), while minute ventilation was lower in hyperoxia (82 ± 18 vs. 93 ± 23 L/min, p < 0.05, all comparisons).
In healthy subjects, hyperoxia increased maximal power output and endurance. It improved arterial, cerebral, and muscle tissue oxygenation, while minute ventilation and dyspnea perception were reduced. The findings suggest that hyperoxia enhanced cycling performance through a more efficient pulmonary gas exchange and a greater availability of oxygen to muscles and the brain (cerebral motor and sensory neurons).
高氧对运动受限的影响仍未完全明确。
我们研究了呼吸高氧在多大程度上能提高健康受试者的运动表现以及涉及哪些生理机制。
共有32名健康志愿者（43±15岁，12名女性），在不同时间分别按照随机、盲法顺序进行4次自行车运动测试直至力竭，采用斜坡递增和恒定负荷方案（在FiO₂0.21时最大工作量[Wmax]的75%），同时呼吸室内空气（FiO₂0.21）或富氧空气（FiO₂0.50）。测量工作量、耐力、气体交换、脉搏血氧饱和度（SpO₂）以及脑（CTO）和股四头肌组织氧合（QMTO）。
在FiO₂0.50的斜坡运动最后15秒期间，Wmax（均值±标准差270±80W）、SpO₂（99±1%）和CTO（67±9%）更高，且Borg CR10量表呼吸困难评分更低（4.8±2.2），均低于FiO₂0.21时的相应值（Wmax 257±76W、SpO₂96±3%、CTO 61±9%、Borg CR10量表呼吸困难评分5.7±2.6，p<0.05，所有比较）。在FiO₂0.50的恒定负荷运动中，耐力比FiO₂0.21时更长（16分钟22秒±7分钟39秒对10分钟47秒±5分钟58秒）。在FiO₂0.50时，SpO₂（99±0%）和QMTO（69±8%）高于FiO₂0.21运动结束时的相应等时值（SpO₂96±4%、QMTO 66±9%），而高氧时每分通气量更低（82±18对93±23L/分钟，p<0.05，所有比较）。
在健康受试者中，高氧增加了最大功率输出和耐力。它改善了动脉、脑和肌肉组织氧合，同时降低了每分通气量和呼吸困难感知。研究结果表明，高氧通过更有效的肺气体交换以及向肌肉和大脑（脑运动和感觉神经元）提供更多氧气来提高骑行表现。
