Training in hypoxia: modulation of metabolic and cardiovascular risk factors in men
Training in hypoxia: modulation of metabolic and cardiovascular risk factors in men
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DOI：
10.1097/00005768-200006000-00004
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发表时间：
2000-06-01
期刊：
影响因子：
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通讯作者：
Baker, J
中科院分区：
文献类型：
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作者：
Bailey, DM;Davies, B;Baker, J
目的：本研究旨在确定健康男性在常压低氧运动训练后代谢和心血管危险因素的变化。研究方法：在低氧和/或常氧下进行随机基线最大运动试验后，34名体力活动受试者被随机分配到常氧（N = 14）或低氧（N = 18）训练组。训练包括4周的自行车运动，分别以双盲方式吸入常压常氧（F-IO 2 =类似于20.9%）或常压低氧（F-IO 2 =类似于16.0%）气体。骑自行车运动进行每周三次，20-30分钟，在70-85%的最大心率确定在常氧或缺氧。在运动前和运动后4 d，分别测定了静息时和亚极量和极量运动时的血脂、脂蛋白、总同型半胱氨酸和听诊动脉血压反应的血浆浓度。结果：常氧组和低氧组在训练期间的总功率输出是相同的。仅在低氧训练后，瘦体重增加了1.4 +/- 15 kg（P < 0.001）。在研究过程中，膳食组成和营养素摄入没有改变，但常氧和低氧训练均降低了静息血浆非酯化脂肪酸、总胆固醇、高密度脂蛋白（HDL）和低密度脂蛋白（LDL）的浓度（P < 0.05 - < 0.001）。载脂蛋白AI和B仅在常氧训练后下降（P <或等于0.001）。血浆同型半胱氨酸水平在低氧训练后下降11%（P <0.05），在常氧训练后上升10%（P < 0.05）。这些变化与血清维生素B、和红细胞叶酸的变化无关，后者始终保持稳定。在亚极量运动过程中，观察到乳酸浓度下降，在响应常氧和低氧训练。低氧训练使最大收缩压降低10 +/- 9 mmWg（P < 0.001），心率压积降低14 +/- 23 mm Hg x beats min（-1）/100（P小于或等于0.001），最大摄氧量增加0.47 +/- 0.77 L。min（-1）（P < 0.05）。结论：常氧和低氧训练与选定的危险因素和运动能力的显着改善相关。间歇性常压缺氧刺激引起的心脏保护作用，这可能具有重要的临床意义。
Purpose: This study was designed to determine changes in metabolic and cardiovascular risk factors following normobaric hypoxic exercise training in healthy men. Methods: Following a randomized baseline maximal exercise test in hypoxia and/or normoxia, 34 physically active subjects were randomly assigned to either a normoxic (N = 14) or a hypoxic (N = 18) training group. Training involved 4 wk of cycling exercise inspiring either a normobaric normoxic (F-IO2 = similar to 20.9%) or a normobaric hypoxic (F-IO2, = similar to 16.0%) gas, respectively, in a double-blind manner. Cycling exercise was performed three times per week for 20-30 min at 70-85% of maximum heart rate determined either in normoxia or hypoxia. Resting plasma concentrations of blood lipids, lipoproteins, total homocysteine, and auscultatory arterial blood pressure responses at rest and in response to submaximal and maximal exercise were measured before and 4 d after physical training. Results: Total power output during the training period was identical in both normoxic and hypoxic groups. Lean body mass increased by 1.4 +/- 15 kg following hypoxic training only (P < 0.001). While dietary composition and nutrient intake did not change during the study, both normoxic and hypoxic training decreased resting plasma concentrations of nonesterified fatty acids, total cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL) (P < 0.05 - < 0.001). Apolipoproteins AI and B decreased following normoxic training only (P less than or equal to 0.001). Plasma concentrations of resting total homocysteine decreased by 11% following hypoxic training (P less than or equal to 0.05) and increased by 10% (P < 0.05) following normoxic training. These changes were independent of changes in serum vitamin B,, and red cell folate which remained stable throughout. A decreased lactate concentration during submaximal exercise was observed in response to both normoxic and hypoxic training. Hypoxic training decreased maximal systolic blood pressure by 10 +/- 9 mmWg (P < 0.001) and the rate pressure product by 14 +/- 23 mm Hg x beats min(-1)/100 (P less than or equal to 0.001) and increased maximal oxygen uptake by 0.47 +/- 0.77 L . min(-1) (P < 0.05). Conclusion: Normoxic and hypoxic training was associated with significant improvements in selected risk factors and exercise capacity. The stimulus of intermittent normobaric hypoxia invoked an additive cardioprotective effect which may have important clinical implications.