Branched-chain amino acids (BCAA) and carbohydrate (CHO) are commonly recommended postexercise supplements. However, no study has examined the interaction of CHO and BCAA ingestion on myofibrillar protein synthesis (MyoPS) rates following exercise. We aimed to determine the response of MyoPS to the co-ingestion of BCAA and CHO following an acute bout of resistance exercise. Ten resistance-trained young men completed two trials in counterbalanced order, ingesting isocaloric drinks containing either 30.6-g CHO plus 5.6-g BCAA (B + C) or 34.7-g CHO alone following a bout of unilateral, leg resistance exercise. MyoPS was measured postexercise with a primed, constant infusion of L-[ring¹³C₆] phenylalanine and collection of muscle biopsies pre- and 4 hr postdrink ingestion. Blood samples were collected at time points before and after drink ingestion. Serum insulin concentrations increased to a similar extent in both trials (p > .05), peaking at 30 min postdrink ingestion. Plasma leucine (514 ± 34 nmol/L), isoleucine (282 ± 23 nmol/L), and valine (687 ± 33 nmol/L) concentrations peaked at 0.5 hr postdrink in B + C and remained elevated for 3 hr during exercise recovery. MyoPS was ∼15% greater (95% confidence interval [−0.002, 0.028], p = .039, Cohen’s d = 0.63) in B + C (0.128%/hr ± 0.011%/hr) than CHO alone (0.115%/hr ± 0.011%/hr) over the 4 hr postexercise period. Co-ingestion of BCAA and CHO augments the acute response of MyoPS to resistance exercise in trained young males.

支链氨基酸 (BCAA) 和碳水化合物 (CHO) 是通常推荐的运动后补充剂。然而，尚无研究探讨 CHO 和 BCAA 摄入对运动后肌原纤维蛋白合成 (MyoPS) 率的相互作用。我们的目的是确定在剧烈的抗阻运动后，MyoPS 对同时摄入 BCAA 和 CHO 的反应。10 名接受过阻力训练的年轻人以平衡顺序完成了两项试验，在进行一轮单侧腿部阻力运动后，摄入含有 30.6 克 CHO 加 5.6 克 BCAA (B + C) 或仅 34.7 克 CHO 的等热量饮料。运动后通过预置、持续输注L -[ring ¹³ C ₆] 苯丙氨酸并收集摄入饮料前和 4 小时后的肌肉活检。在摄入饮料之前和之后的时间点采集血样。两项试验中血清胰岛素浓度的增加程度相似 ( p  > .05)，在饮酒后 30 分钟达到峰值。B + C 中血浆亮氨酸 (514 ± 34 nmol/L)、异亮氨酸 (282 ± 23 nmol/L) 和缬氨酸 (687 ± 33 nmol/L) 浓度在饮酒后 0.5 小时达到峰值，并在运动恢复期间保持升高状态 3 小时。MyoPS 增大约 15%（95% 置信区间 [−0.002, 0.028]，p  = .039，Cohen 的d 在运动后 4 小时内，B + C (0.128%/hr ± 0.011%/hr) 中的 B + C (0.128%/hr ± 0.011%/hr) 比单独使用 CHO (0.115%/hr ± 0.011%/hr) 的结果要低 (0.63)。BCAA 和 CHO 的共同摄入增强了受过训练的年轻男性的 MyoPS 对抗阻运动的急性反应。