Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Ontario, Canada.
Med Sci Sports Exerc. 2009 Dec;41(12):2158-64. doi: 10.1249/MSS.0b013e3181ac10bf.
Ingesting protein (PRO) with CHO during prolonged exercise is purported to improve performance compared with CHO alone by altering the regulation of skeletal muscle energy provision. However, no study has directly investigated this issue. We tested the hypothesis that compared with CHO alone, coingestion of PRO would alter markers of metabolic control, including the magnitude of glycogen use and the net expansion of the tricarboxylic acid cycle intermediate pool, which has been linked to the capacity for oxidative energy delivery.
Eight trained men (mean +/- SE: age = 29 +/- 2 yr; VO2peak = 55 +/- 2 mL x kg(-1) x min(-1)) cycled at 69% +/- 1% VO2peak for 90 min on two occasions, and biopsy samples (vastus lateralis) were obtained before and after exercise. In a randomized, double-blind manner, subjects ingested one of two drinks during exercise that contained either 6% CHO or 6% CHO + 2% PRO (CHO + PRO) at a rate of 1 L x h(-1) to deliver 60 g x h(-1) CHO +/- 20 g x h(-1) PRO.
CHO + PRO ingestion increased the plasma concentration of branched chain (561 +/- 46 vs 301 +/- 32 micromol x L(-1)) and essential amino acids (1071 +/- 98 vs 670 +/- 71 micromol x L(-1)) after exercise versus CHO (both P values <or=0.05). However, net muscle glycogen use (CHO + PRO = 223 +/- 31 vs CHO = 185 +/- 38 mmol x kg(-1) dry weight) and tricarboxylic acid cycle intermediate expansion (CHO + PRO = 2.3 +/- 0.7 vs CHO = 2.1 +/- 0.2 mmol x kg(-1) dry weight) were similar between trials. Blood creatine kinase activity and 20-km time trial performance measured approximately 24 h after the first exercise bout were not different between treatments.
When trained men ingest CHO at a rate on the upper end of the range generally recommended to improve endurance performance, coingestion of PRO does not alter specific markers proposed to reflect an enhanced capacity for skeletal muscle energy delivery.
在长时间运动中摄入蛋白质（PRO）与碳水化合物（CHO）相比，据称可以通过改变骨骼肌能量供应的调节来提高运动表现。然而，尚无研究直接研究这个问题。我们假设与单独 CHO 相比，同时摄入 PRO 将改变代谢控制的标志物，包括糖原使用的幅度和三羧酸循环中间产物池的净扩张，这与氧化能量传递的能力有关。
8 名训练有素的男性（平均 +/- SE：年龄 = 29 +/- 2 岁；峰值 VO2 = 55 +/- 2 mL x kg(-1) x min(-1)）在 2 次情况下以 69% +/- 1% VO2peak 进行 90 分钟的自行车运动，并且在运动前和运动后获得股外侧肌活检样本。以随机、双盲的方式，受试者在运动期间以 1 L x h(-1) 的速度摄入两种饮料中的一种，其中含有 6% CHO 或 6% CHO + 2% PRO（CHO + PRO），以输送 60 g x h(-1) CHO +/- 20 g x h(-1) PRO。
与 CHO（均 P 值 <= 0.05）相比，CHO + PRO 摄入使运动后血浆中支链（561 +/- 46 对 301 +/- 32 微摩尔 x L(-1)）和必需氨基酸（1071 +/- 98 对 670 +/- 71 微摩尔 x L(-1)）的浓度升高。然而，净肌肉糖原利用（CHO + PRO = 223 +/- 31 对 CHO = 185 +/- 38 mmol x kg(-1) 干重）和三羧酸循环中间产物扩张（CHO + PRO = 2.3 +/- 0.7 对 CHO = 2.1 +/- 0.2 mmol x kg(-1) 干重）在两次试验之间相似。第一次运动后的大约 24 小时测量的血液肌酸激酶活性和 20 公里计时赛表现，在治疗之间没有差异。
当训练有素的男性以一般建议提高耐力表现的上限速度摄入 CHO 时，同时摄入 PRO 不会改变被提议反映骨骼肌能量传递能力增强的特定标志物。
