Perry Christopher G R, Heigenhauser George J F, Bonen Arend, Spriet Lawrence L
Department of Human Health and Nutritional Sciences, University of Guelph, ON N1G 2W1, Canada.
Appl Physiol Nutr Metab. 2008 Dec;33(6):1112-23. doi: 10.1139/H08-097.
High-intensity aerobic interval training (HIIT) is a compromise between time-consuming moderate-intensity training and sprint-interval training requiring all-out efforts. However, there are few data regarding the ability of HIIT to increase the capacities of fat and carbohydrate oxidation in skeletal muscle. Using untrained recreationally active individuals, we investigated skeletal muscle and whole-body metabolic adaptations that occurred following 6 weeks of HIIT (~1 h of 10 x 4 min intervals at ~90% of peak oxygen consumption (VO2 peak), separated by 2 min rest, 3 d.week-1). A VO2 peak test, a test to exhaustion (TE) at 90% of pre-training VO2 peak, and a 1 h cycle at 60% of pre-training VO2 peak were performed pre- and post-HIIT. Muscle biopsies were sampled during the TE at rest, after 5 min, and at exhaustion. Training power output increased by 21%, and VO2 peak increased by 9% following HIIT. Muscle adaptations at rest included the following: (i) increased cytochrome c oxidase IV content (18%) and maximal activities of the mitochondrial enzymes citrate synthase (26%), beta-hydroxyacyl-CoA dehydrogenase (29%), aspartate-amino transferase (26%), and pyruvate dehydrogenase (PDH; 21%); (ii) increased FAT/CD36, FABPpm, GLUT 4, and MCT 1 and 4 transport proteins (14%-30%); and (iii) increased glycogen content (59%). Major adaptations during exercise included the following: (i) reduced glycogenolysis, lactate accumulation, and substrate phosphorylation (0-5 min of TE); (ii) unchanged PDH activation (carbohydrate oxidation; 0-5 min of TE); (iii) ~2-fold greater time during the TE; and (iv) increased fat oxidation at 60% of pre-training VO2 peak. This study demonstrated that 18 h of repeated high-intensity exercise sessions over 6 weeks (3 d.week-1) is a powerful method to increase whole-body and skeletal muscle capacities to oxidize fat and carbohydrate in previously untrained individuals.
高强度有氧间歇训练（HIIT）是耗时的中等强度训练和需要全力冲刺的间歇训练之间的一种折衷方式。然而，关于HIIT增加骨骼肌中脂肪和碳水化合物氧化能力的数据很少。我们以未经训练但有运动习惯的个体为研究对象，调查了进行6周HIIT（每周3天，每次约1小时，包含10组4分钟的训练，强度约为峰值摄氧量（VO2峰值）的90%，组间休息2分钟）后骨骼肌和全身的代谢适应性变化。在HIIT前后分别进行了VO2峰值测试、在训练前VO2峰值的90%强度下进行力竭测试（TE）以及在训练前VO2峰值的60%强度下进行1小时的骑行测试。在TE过程中，分别于静息时、5分钟后和力竭时采集肌肉活检样本。HIIT后，训练功率输出增加了21%，VO2峰值增加了9%。静息时的肌肉适应性变化包括：（i）细胞色素c氧化酶IV含量增加（18%），线粒体酶柠檬酸合酶（26%）、β-羟酰基辅酶A脱氢酶（29%）、天冬氨酸氨基转移酶（26%）和丙酮酸脱氢酶（PDH；21%）的最大活性增加；（ii）FAT/CD36、FABPpm、GLUT 4以及MCT 1和4转运蛋白增加（14%-30%）；（iii）糖原含量增加（59%）。运动过程中的主要适应性变化包括：（i）糖原分解、乳酸积累和底物磷酸化减少（TE的0-5分钟）；（ii）PDH激活不变（碳水化合物氧化；TE的0-5分钟）；（iii）TE过程中的时间延长约2倍；（iv）在训练前VO2峰值的60%强度下脂肪氧化增加。这项研究表明，在6周内（每周3天）进行18小时的重复高强度训练是一种有效的方法，可以提高未受过训练的个体全身和骨骼肌氧化脂肪和碳水化合物的能力。
