Willoughby D S, Stout J R, Wilborn C D
Exercise and Biochemical Nutrition Laboratory, Baylor University, Waco, Texas 76798, U.S.A.
Amino Acids. 2007;32(4):467-77. doi: 10.1007/s00726-006-0398-7. Epub 2006 Sep 20.
This study examined 10 wks of resistance training and the ingestion of supplemental protein and amino acids on muscle performance and markers of muscle anabolism. Nineteen untrained males were randomly assigned to supplement groups containing either 20 g protein (14 g whey and casein protein, 6 g free amino acids) or 20 g dextrose placebo ingested 1 h before and after exercise for a total of 40 g/d. Participants exercised 4 times/wk using 3 sets of 6-8 repetitions at 85-90% of the one repetition maximum. Data were analyzed with two-way ANOVA (p < 0.05). The protein supplement resulted in greater increases in total body mass, fat-free mass, thigh mass, muscle strength, serum IGF-1, IGF-1 mRNA, MHC I and IIa expression, and myofibrillar protein. Ten-wks of resistance training with 20 g protein and amino acids ingested 1 h before and after exercise is more effective than carbohydrate placebo in up-regulating markers of muscle protein synthesis and anabolism along with subsequent improvements in muscle performance.
本研究考察了为期10周的抗阻训练以及补充蛋白质和氨基酸对肌肉性能和肌肉合成代谢标志物的影响。19名未经训练的男性被随机分配到补充组，一组在运动前后1小时摄入20克蛋白质（14克乳清蛋白和酪蛋白，6克游离氨基酸），另一组摄入20克葡萄糖安慰剂，每天总量为40克。参与者每周锻炼4次，每组进行3组，每组6 - 8次重复，强度为一次重复最大值的85 - 90%。采用双向方差分析对数据进行分析（p < 0.05）。蛋白质补充剂使总体重、去脂体重、大腿围度、肌肉力量、血清胰岛素样生长因子-1（IGF-1）、IGF-1 mRNA、肌球蛋白重链I和IIa表达以及肌原纤维蛋白有更大程度的增加。在运动前后1小时摄入20克蛋白质和氨基酸并进行10周的抗阻训练，在上调肌肉蛋白质合成和合成代谢标志物以及随后改善肌肉性能方面比碳水化合物安慰剂更有效。
