a Child Health & Exercise Medicine Program, Department of Pediatrics, McMaster University, Hamilton, ON L8S 4K1, Canada.
b Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2C9, Canada.
Appl Physiol Nutr Metab. 2017 Nov;42(11):1142-1148. doi: 10.1139/apnm-2017-0185. Epub 2017 Jul 6.
The dose and timing of postexercise protein ingestion can influence whole-body protein balance (WBPB) in adults, although comparable data from children are scarce. This study investigated how protein intake (both amount and distribution) postexercise can affect WBPB in physically active children. Thirty-five children (26 males; 9-13 years old) underwent a 5-day adaptation diet, maintaining a protein intake of 0.95 g·kg·day. Participants consumed [N]glycine (2 mg·kg) before performing 3 × 20 min of variable-intensity cycling, and whole-body protein kinetics were assessed over 6 and 24 h of recovery. Fifteen grams of protein was distributed across 2 isoenergetic carbohydrate-containing beverages (15 and 240 min postexercise) containing reciprocal amounts of protein (i.e., 0 + 15 g, 5 + 10 g, 10 + 5 g, and 15 + 0 g for Groups A-D, respectively). Over the 6 h that included the exercise bout and consumption of the first beverage at 15 min postexercise, WBPB (i.e., synthesis - breakdown) demonstrated a linear increase of 0.647 g·kg·day per 1 g protein intake (P < 0.001). Over 24 h, robust regression revealed that WBPB was best modeled by a parabola (P < 0.05), suggesting that a maximum in WBPB was achieved between groups B and C. In conclusion, despite a dose response early in recovery, a periodized protein intake with multiple smaller doses after physical activity may be more beneficial than a single bolus dose in promoting daily WBPB in healthy active children.
运动后蛋白质的摄入剂量和时间会影响成年人的全身蛋白质平衡（WBPB），但儿童的数据相对较少。本研究旨在探讨运动后蛋白质的摄入（摄入量和分布）如何影响活跃儿童的 WBPB。35 名儿童（26 名男性；9-13 岁）进行了为期 5 天的适应饮食，保持蛋白质摄入量为 0.95 g·kg·day。参与者在进行 3 次 20 分钟不等强度的循环运动前，先摄入 [N]甘氨酸（2 mg·kg），并在恢复的 6 小时和 24 小时期间评估全身蛋白质动力学。15 克蛋白质分布在 2 种含有等能量碳水化合物的饮料中（运动后 15 分钟和 240 分钟），其中含有等量的蛋白质（即 A-D 组分别为 0+15 g、5+10 g、10+5 g 和 15+0 g）。在包括运动回合和在 15 分钟后饮用第一份饮料的 6 小时期间，WBPB（即合成-分解）呈现线性增加，每摄入 1 克蛋白质增加 0.647 g·kg·day（P<0.001）。在 24 小时内，强大的回归分析显示，WBPB 最好由抛物线来建模（P<0.05），这表明在 B 组和 C 组之间达到了 WBPB 的最大值。总之，尽管在恢复早期存在剂量反应，但在体力活动后分多个较小剂量摄入蛋白质可能比单次大剂量摄入更有利于促进健康活跃儿童的日常 WBPB。
