NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ (MUMC+) , Maastricht , The Netherlands.
Stable Isotope Research Center (SIRC), Maastricht University Medical Center+ (MUMC+) , Maastricht , The Netherlands.
J Appl Physiol (1985). 2018 Jan 1;124(1):66-75. doi: 10.1152/japplphysiol.00610.2017. Epub 2017 Sep 21.
Resistance-type exercise increases muscle protein synthesis rates during acute postexercise recovery. The impact of resistance-type exercise training on (local) muscle protein synthesis rates under free-living conditions on a day-to-day basis remains unclear. We determined the impact of daily unilateral resistance-type exercise on local myofibrillar protein synthesis rates during a 3-day period. Twelve healthy young men (22 ± 1 yr) were recruited to participate in this study where they performed daily, unilateral resistance-type exercise during a 3-day intervention period. Two days before the exercise training subjects ingested 400 ml deuterated water (HO). Additional 50-ml doses of deuterated water were ingested daily during the training period. Saliva and blood samples were collected daily to assess body water and amino acid precursor deuterium enrichments, respectively. Muscle tissue biopsies were collected before and after the 3 days of unilateral resistance-type exercise training from both the exercised and the nonexercised, control leg for the assessment of muscle protein synthesis rates. Deuterated water dosing resulted in a steady-state body water enrichment of 0.70 ± 0.03%. Intramuscular free [H]alanine enrichment increased up to 1.84 ± 0.06 mole percent excess (MPE) before the exercise training and did not change in both the exercised and control leg during the 3 subsequent exercise training days (2.11 ± 0.11 and 2.19 ± 0.12 MPE, respectively; P > 0.05). Muscle protein synthesis rates averaged 1.984 ± 0.118 and 1.642 ± 0.089%/day in the exercised vs. nonexercised, control leg when assessed over the entire 3-day period ( P < 0.05). Daily resistance-type exercise stimulates (local) muscle protein synthesis in vivo in humans. NEW & NOTEWORTHY This study demonstrates that daily resistance-type exercise stimulates muscle protein synthesis rates in vivo in humans over multiple days. Whereas acute studies have shown that resistance-type exercise increases muscle protein synthesis rates by 50-100%, we observed a lower impact of resistance-type exercise under free-living conditions. We also compared precursor tracer selection for the calculation of muscle protein synthesis rates and observed that saliva deuterium enrichment serves as an appropriate and practical choice of precursor.
抗阻运动可增加急性运动后恢复期的肌肉蛋白质合成速率。然而，在日常生活中，抗阻运动训练对（局部）肌肉蛋白质合成速率的影响尚不清楚。本研究旨在确定为期 3 天的日常单侧抗阻运动对局部肌纤维蛋白合成速率的影响。招募了 12 名健康的年轻男性（22 ± 1 岁）参与本研究，他们在 3 天的干预期间每天进行单侧抗阻运动。在运动训练前 2 天，受试者摄入 400ml 氘水（HO）。在训练期间，每天额外摄入 50ml 氘水。每天采集唾液和血液样本，分别评估体水和氨基酸前体氘的富集情况。在 3 天单侧抗阻运动训练前后，从运动和非运动的对照腿采集肌肉组织活检，以评估肌肉蛋白质合成速率。氘水给药导致体水稳定状态富集 0.70 ± 0.03%。在运动训练前，肌肉内游离[H]丙氨酸富集增加到 1.84 ± 0.06 摩尔分超额（MPE），而在随后的 3 天运动训练中，运动和对照腿的游离[H]丙氨酸富集均未发生变化（分别为 2.11 ± 0.11 和 2.19 ± 0.12 MPE；P > 0.05）。在整个 3 天期间，运动腿和非运动腿的肌肉蛋白质合成速率分别平均为 1.984 ± 0.118%/天和 1.642 ± 0.089%/天（P < 0.05）。本研究表明，日常抗阻运动可在多日内在体内刺激肌肉蛋白质合成。急性研究表明，抗阻运动可使肌肉蛋白质合成速率增加 50-100%，而本研究观察到在日常生活条件下，抗阻运动的影响较低。我们还比较了用于计算肌肉蛋白质合成速率的前体示踪剂选择，发现唾液氘富集是一种合适且实用的前体选择。
