Ji Xiaorong, Ye Xuanyin, Ji Shuyi, Zhang Shuxin, Wang Yuwen, Zhou Zhibei, Xiang Dao, Luo Beibei
Shanghai Key Laboratory of Human Performance, Shanghai University of Sport, Shanghai 200438, China.
School of Exercise and Health, Shanghai University of Sport, Shanghai 200438, China.
Nutrients. 2025 Aug 8;17(16):2579. doi: 10.3390/nu17162579.
The process of muscle protein synthesis (MPS) plays a pivotal role in the enhancement of muscle function. Following a bout of exercise, the rate of MPS experiences an elevation for a brief period, known as the "anabolic window." Despite whey protein supplementation has been demonstrated to augment the post-exercise anabolic window, the optimal timing and dosage remain controversial. Therefore, the present systematic review and meta-analysis were conducted to evaluate the effects of whey protein supplementation on post-exercise MPS and its protein kinase B (AKT)/mammalian target of the rapamycin (mTOR) pathway in healthy adults. Following PRISMA guidelines, this review included 21 RCTs, with 15 studies subjected to meta-analysis and 6 studies to qualitative analysis. Eligible studies examined myofibrillar fractional synthetic rate (FSR) or the AKT/mTOR pathway-related protein phosphorylation levels in muscle biopsy samples. The combination of whey protein supplementation and exercise has been shown to significantly enhance FSR (Hedge's g = 1.24, 95% CI: 0.71-1.77; < 0.001), with increases ranging from 1.3 to 1.6 folds when consumed immediately after exercise and up to 2.5 folds when given 45 min prior to multiple-set resistance exercise. A dose-dependent increase in FSR was observed in response to whey protein supplementation, ranging from 10 to 60 g. In comparison to the placebo group, whey protein supplementation enhanced the phosphorylation levels of AKT, mTOR, eukaryotic translation initiation factor 4E-binding protein-1 (4E-BP1), 70 kDa ribosomal protein S6 kinase (p70S6K), and ribosomal protein S6 (rpS6) at 1-2 h post-exercise. Phosphorylation levels of p70S6K and rpS6 decreased 4-5 h after exercise. The combination of whey protein supplementation and exercise improves MPS in a time- and dose-dependent manner. Consumption of 20-40g of whey protein before multiple sets of resistance exercise may enhance myofibrillar FSR and activate the AKT/mTOR pathway, thereby augmenting MPS and extending the anabolic window.
肌肉蛋白质合成（MPS）过程在增强肌肉功能方面起着关键作用。一次运动后，MPS速率会在短时间内升高，这一时期被称为“合成代谢窗口”。尽管已证明补充乳清蛋白可扩大运动后的合成代谢窗口，但最佳时间和剂量仍存在争议。因此，本系统评价和荟萃分析旨在评估补充乳清蛋白对健康成年人运动后MPS及其蛋白激酶B（AKT）/雷帕霉素哺乳动物靶蛋白（mTOR）信号通路的影响。遵循PRISMA指南，本评价纳入了21项随机对照试验，其中15项研究进行荟萃分析，6项研究进行定性分析。符合条件的研究检测了肌肉活检样本中的肌原纤维分数合成率（FSR）或AKT/mTOR信号通路相关蛋白的磷酸化水平。补充乳清蛋白与运动相结合已被证明能显著提高FSR（Hedge's g = 1.24，95%CI：0.71 - 1.77；P < 0.001），运动后立即摄入时增加幅度为1.3至1.6倍，在多组抗阻运动前45分钟摄入时增加幅度高达2.5倍。观察到FSR随乳清蛋白补充剂量的增加而呈剂量依赖性增加，范围为10至60克。与安慰剂组相比，补充乳清蛋白可提高运动后1 - 2小时AKT、mTOR、真核翻译起始因子4E结合蛋白1（4E - BP1）、70 kDa核糖体蛋白S6激酶（p70S6K）和核糖体蛋白S6（rpS6）的磷酸化水平。运动后4 - 5小时，p70S6K和rpS6的磷酸化水平下降。补充乳清蛋白与运动相结合可在时间和剂量依赖的方式下改善MPS。在多组抗阻运动前摄入20 - 40克乳清蛋白可能会提高肌原纤维FSR并激活AKT/mTOR信号通路，从而增强MPS并延长合成代谢窗口。
