Haufe Sven, Wiesner Susanne, Engeli Stefan, Luft Friedrich C, Jordan Jens
Franz Volhard Clinical Research Center, Medical Faculty of the Charité, Berlin, Germany.
Med Sci Sports Exerc. 2008 Nov;40(11):1939-44. doi: 10.1249/MSS.0b013e31817f1988.
Endurance exercise and hypoxia regulate pathways that are crucial to glucose and lipid metabolism. We hypothesized that training under hypoxia results in similar or even greater metabolic improvement compared with exercise under normoxia at a lower workload.
We randomly assigned 20 healthy men to single blind training under hypoxia (FiO2 = 15%) or normoxia (FiO2 = 21%). Subjects trained thrice weekly for 60 min over a 4-wk period at a heart rate measured at 3 mmol x L(-1) lactate during pretraining exercise testing. Before and after the training period, we determined body composition, venous blood parameters, oral glucose tolerance, and blood pressure. Furthermore, we assessed oxygen uptake (VO2), lactate, and respiratory quotient, and heart rate (HR) during incremental exercise testing, both in hypoxia and in normoxia. Training workload was 1.39 +/- 0.2 W x kg(-1) in the hypoxia and 1.67 +/- 0.15 W x kg(-1) in the normoxia group (P< 0.001) with an identical training heart rate in both groups.
Exercise capacity improved similarly with both interventions. With hypoxia training, body fat content, triglycerides, HOMA-Index, fasting insulin (P < 0.05), and area under the curve for insulin (P < 0.01) during the oral glucose tolerance test improved more than with the training in normoxia. We did not observe major changes in adipokine measurements.
Endurance training in hypoxia over a 4-wk period elicits a similar or even better response in terms of cardiovascular and metabolic risk factors than endurance exercise in normoxia. The fact that workload and, therefore, mechanic strain can be reduced in hypoxia could be particularly beneficial in obese patients and in patients with orthopedic conditions.
耐力运动和低氧状态可调节对葡萄糖和脂质代谢至关重要的途径。我们假设，与在较低工作量的常氧环境下运动相比，低氧环境下训练能带来相似甚至更大的代谢改善。
我们将20名健康男性随机分配至单盲低氧（吸入氧分数=15%）或常氧（吸入氧分数=21%）训练组。在预训练运动测试期间，受试者以3 mmol/L乳酸时测得的心率为标准，每周训练三次，每次60分钟，为期4周。在训练期前后，我们测定了身体成分、静脉血参数、口服葡萄糖耐量和血压。此外，我们在低氧和常氧递增运动测试期间评估了摄氧量（VO₂）、乳酸和呼吸商以及心率（HR）。低氧组的训练工作量为1.39±0.2 W/kg⁻¹，常氧组为1.67±0.15 W/kg⁻¹（P<0.001），两组训练心率相同。
两种干预方式的运动能力均有相似改善。低氧训练后，身体脂肪含量、甘油三酯、HOMA指数、空腹胰岛素（P<0.05）以及口服葡萄糖耐量测试期间胰岛素曲线下面积（P<0.01）的改善程度均大于常氧训练。我们未观察到脂肪因子测量有重大变化。
为期4周的低氧耐力训练在心血管和代谢危险因素方面引发的反应与常氧耐力运动相似甚至更好。低氧环境下工作量以及机械应变可降低这一事实，对肥胖患者和骨科疾病患者可能特别有益。
