OBJECTIVE Exercise training is a cornerstone of the treatment of chronic obstructive pulmonary disease, whereas the related interindividual heterogeneity in skeletal muscle dysfunction and adaptations are not yet fully understood. We set out to investigate the effects of exercise training and supplemental oxygen on functional and structural peripheral muscle adaptation. METHODS In this prospective, randomized, controlled, double-blind study, 28 patients with nonhypoxemic chronic obstructive pulmonary disease (forced expiratory volume in 1 second, 45.92% ± 9.06%) performed 6 wk of combined endurance and strength training, three times a week while breathing either supplemental oxygen or medical air. The impact on exercise capacity, muscle strength, and quadriceps femoris muscle cross-sectional area (CSA) was assessed by maximal cardiopulmonary exercise testing, 10-repetition maximum strength test of knee extension, and magnetic resonance imaging, respectively. RESULTS After exercise training, patients demonstrated a significant increase in functional capacity, aerobic capacity, exercise tolerance, quadriceps muscle strength, and bilateral CSA. Supplemental oxygen affected significantly the training impact on peak work rate when compared with medical air (+0.20 ± 0.03 vs +0.12 ± 0.03 W·kg -1 , P = 0.047); a significant increase in CSA (+3.9 ± 1.3 cm 2 , P = 0.013) was only observed in the training group using oxygen. Supplemental oxygen and exercise-induced peripheral desaturation were identified as significant opposing determinants of muscle gain during this exercise training intervention, which led to different adaptations of CSA between the respective subgroups. CONCLUSIONS The heterogenous functional and structural muscle adaptations seem determined by supplemental oxygen and exercise-induced hypoxia. Indeed, supplemental oxygen may facilitate muscular training adaptations, particularly in limb muscle dysfunction, thereby contributing to the enhanced training responses on maximal aerobic and functional capacity.

中文翻译：

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运动训练和补充氧气对慢性阻塞性肺疾病周围肌肉的影响：随机对照试验。

目的运动训练是治疗慢性阻塞性肺疾病的基石，而骨骼肌功能障碍和适应的相关个体间异质性尚未完全了解。我们着手研究运动训练和补充氧气对外周肌肉功能和结构适应的影响。方法 在这项前瞻性、随机、对照、双盲研究中，28 名非低氧血症慢性阻塞性肺疾病患者（1 秒用力呼气量，45.92% ± 9.06%）进行了 6 周的耐力和力量联合训练，每周 3 次同时呼吸补充氧气或医用空气。分别通过最大心肺运动测试、10次重复膝关节伸展最大力量测试和磁共振成像来评估对运动能力、肌肉力量和股四头肌横截面积（CSA）的影响。结果运动训练后，患者的功能能力、有氧能力、运动耐量、股四头肌力量和双侧 CSA 均显着增加。与医用空气相比，补充氧气显着影响训练对峰值工作率的影响（+0.20 ± 0.03 vs +0.12 ± 0.03 W·kg -1 ，P = 0.047）；仅在使用氧气的训练组中观察到 CSA 显着增加（+3.9 ± 1.3 cm 2 ，P = 0.013）。补充氧气和运动引起的外周去饱和被认为是运动训练干预期间肌肉增长的重要相反决定因素，这导致各个亚组之间 CSA 的适应不同。结论 异质的功能和结构肌肉适应似乎是由补充氧气和运动引起的缺氧决定的。事实上，补充氧气可以促进肌肉训练适应，特别是在肢体肌肉功能障碍中，从而有助于增强最大有氧和功能能力的训练反应。