Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, NORWAY, and.
Section of Anatomy, Institute of Basis Medical Sciences, University of Oslo, Oslo, NORWAY.
Med Sci Sports Exerc. 2019 Jan;51(1):75-83. doi: 10.1249/MSS.0000000000001758.
A rapid digestibility and high leucine content are considered important for maximal stimulation of muscle protein synthesis. Consequently, with these properties, native whey may hold greater anabolic potential than milk, when supplemented in combination with strength training. Our aim was to compare the effects of supplementation with milk or native whey, during a 12-wk strength training period, on gains in muscle mass and strength in young adults.
In this double-blinded, randomized, controlled study a total of 40 untrained young men and women received two daily servings of either milk or native whey containing 20 g of protein, during a 12-wk strength training intervention. Muscle strength, lean mass, thigh muscle cross-sectional area, m. vastus lateralis thickness and muscle fiber cross-sectional area were assessed before and after the training period. In addition, the acute phosphorylation of the anabolic kinases p70S6K, 4E-BP1 and eEF-2 in response to a standardized workout and supplementation was investigated before and after the 12-wk training period.
Muscle mass and strength increased, by all measures applied (5%-16%, P < 0.001), with no differences between groups (P > 0.25). p70S6K phosphorylation increased (~1000%, P < 0.02) 2 h after exercise in the untrained and trained state, but no differences in anabolic signaling were observed between supplements (P > 0.40). No correlation between these acute measures and changes in muscle mass or strength were observed.
Supplementation with milk or native whey during a 12-wk strength training period did not differentially affect muscle mass and strength in young untrained individuals.
快速消化和高亮氨酸含量被认为是最大程度刺激肌肉蛋白质合成的重要因素。因此，与牛奶相比，天然乳清在与力量训练结合补充时可能具有更大的合成代谢潜力。我们的目的是比较在 12 周力量训练期间补充牛奶或天然乳清对年轻成年人肌肉质量和力量增加的影响。
在这项双盲、随机、对照研究中，共有 40 名未经训练的年轻男性和女性在 12 周的力量训练干预期间每天接受两次含有 20 克蛋白质的牛奶或天然乳清补充。在训练前和训练后评估肌肉力量、瘦体重、大腿肌肉横截面积、股外侧肌厚度和肌肉纤维横截面积。此外，还在训练前和 12 周训练后研究了急性肌肉合成代谢激酶 p70S6K、4E-BP1 和 eEF-2 对标准化锻炼和补充的磷酸化反应。
所有应用的指标（5%-16%，P<0.001）均显示肌肉质量和力量增加，两组之间无差异（P>0.25）。在未经训练和训练状态下，运动后 2 小时 p70S6K 磷酸化增加（~1000%，P<0.02），但两种补充剂之间的合成代谢信号无差异（P>0.40）。这些急性指标与肌肉质量或力量的变化之间没有相关性。
在 12 周力量训练期间补充牛奶或天然乳清不会对年轻未训练个体的肌肉质量和力量产生差异影响。
