Burgess W A, Davis J M, Bartoli W P, Woods J A
Dept. of Pathology, University of South Carolina School of Medicine, Columbia.
Int J Sport Nutr. 1991 Dec;1(4):338-52. doi: 10.1123/ijsn.1.4.338.
The effects of ingesting a low dose of CHO on plasma glucose, glucoregulatory hormone responses, and performance during prolonged cycling were investigated. Nine male subjects cycled for 165 min at approximately 67% peak VO2 followed by a two-stage performance ride to exhaustion on two occasions in the laboratory. Every 20 min during exercise, subjects consumed either a flavored water placebo (P) or a dilute carbohydrate beverage (C). Blood samples were collected immediately before, every 20 min throughout, and immediately after exercise. Plasma was analyzed for glucose, lactate, free fatty acids (FFA), and various glucoregulatory hormones. VO2, RER, heart rate, perceived exertion, and exercise performance were also measured. Lactate, FFA, epinephrine, norepinephrine, ACTH, cortisol, and glucagon increased with exercise whereas glucose and insulin decreased (p < or = .05). Except for a small difference in glucose at 158 min of exercise and at exhaustion, no significant differences were found between drinks for any of the variables studied (P > or = .05). Ingestion of 13 g carbohydrate per hour is not sufficient to maintain plasma glucose, attenuate the glucoregulatory hormone response, and improve performance during prolonged moderate intensity cycling.
研究了摄入低剂量碳水化合物（CHO）对长时间骑行期间血浆葡萄糖、糖调节激素反应和运动表现的影响。九名男性受试者在实验室中进行了两次实验，先以约67%的峰值摄氧量骑行165分钟，然后进行两阶段的力竭性骑行。运动期间每隔20分钟，受试者饮用调味水安慰剂（P）或稀释碳水化合物饮料（C）。在运动前、运动全程每隔20分钟以及运动后立即采集血样。分析血浆中的葡萄糖、乳酸、游离脂肪酸（FFA）和各种糖调节激素。还测量了摄氧量、呼吸商、心率、主观用力程度和运动表现。运动时乳酸、FFA、肾上腺素、去甲肾上腺素、促肾上腺皮质激素、皮质醇和胰高血糖素增加，而葡萄糖和胰岛素减少（p≤0.05）。除了运动158分钟和力竭时葡萄糖有微小差异外，所研究的任何变量在两种饮料之间均未发现显著差异（P≥0.05）。每小时摄入13克碳水化合物不足以维持血浆葡萄糖水平、减弱糖调节激素反应以及改善长时间中等强度骑行期间的运动表现。
