Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Center for Bone Diseases, Lausanne University Hospital, Lausanne, Switzerland.
Obesity (Silver Spring). 2018 May;26(5):819-827. doi: 10.1002/oby.22131. Epub 2018 Mar 25.
The aim of this study was to compare the effects of short-term hypoxic versus normoxic training at preferred walking speed (PWS) on energetics, mechanics, efficiency, and metabolic risk markers in individuals with obesity.
Twenty-three subjects with obesity performed nine 1-hour sessions at PWS under hypoxia (3,000 m, n = 12; BMI: 34.0 ± 0.8 kg/m ) or normoxia (360 m, n = 11; BMI: 32.9 ± 0.8 kg/m ). Participants performed six 5-minute walking trials at different speeds (PWS, 0.56, 0.83, 1.11, 1.39, and 1.67 m/s). The net energy cost, external mechanical work, and rated perceived exertion (RPE) were measured at these speeds. Body composition and blood samples were collected.
PWS tended to be slower under hypoxia than normoxia (-6.7%; P = 0.092) during the training, and this difference reached significance the third week (-8.9%; P = 0.05). After training, PWS significantly increased (+ 8.2%; P ≤ 0.001), while RPE decreased (P = 0.005). Ankle range of motion (P = 0.03) and vertical displacement of the center of mass (P = 0.02) significantly increased in both groups.
A walking training program under hypoxia at slower PWS than in normoxia elicited similar responses in metabolic risk factors, energetics, and mechanics of walking in individuals with obesity. Both programs increased PWS, decreased RPE, and induced gait-pattern adaptations, which protected against orthopedic injury in these individuals.
本研究旨在比较短时间低氧与常氧下以个体习惯步行速度（PWS）进行训练对肥胖者能量代谢、力学、效率和代谢风险标志物的影响。
23 名肥胖者在低氧（3000 米，n=12；BMI：34.0±0.8 kg/m ）或常氧（360 米，n=11；BMI：32.9±0.8 kg/m ）下以 PWS 进行 9 次 1 小时的训练。参与者在不同速度（PWS、0.56、0.83、1.11、1.39 和 1.67 m/s）下进行 6 次 5 分钟的步行试验。在这些速度下测量净能量消耗、外部机械功和主观体力感觉等级（RPE）。采集身体成分和血液样本。
在训练过程中，低氧下的 PWS 比常氧下的 PWS 慢（-6.7%；P=0.092），且在第三周时差异具有统计学意义（-8.9%；P=0.05）。训练后，PWS 显著增加（+8.2%；P≤0.001），而 RPE 降低（P=0.005）。两组踝关节活动范围（P=0.03）和质心垂直位移（P=0.02）均显著增加。
与常氧下相比，以较慢 PWS 进行的低氧步行训练计划在肥胖者的代谢风险因素、能量代谢和步行力学方面产生了相似的反应。两种方案均增加了 PWS，降低了 RPE，并引起了步态模式的适应性改变，从而保护了这些个体免受骨科损伤。
