Laboratory of Exercise Physiology, SSC RF Institute of Biomedical Problems of Russian Academy of Sciences, Moscow, Russia; and.
Faculty of Fundamental Medicine, M. V. Lomonosov Moscow State University, Moscow, Russia.
J Strength Cond Res. 2020 Apr;34(4):1103-1112. doi: 10.1519/JSC.0000000000002901.
Lysenko, EA, Popov, DV, Vepkhvadze, TF, Sharova, AP, and Vinogradova, OL. Moderate-intensity strength exercise to exhaustion results in more pronounced signaling changes in skeletal muscles of strength-trained compared with untrained individuals. J Strength Cond Res 34(4): 1103-1112, 2020-The aim of our investigation was to compare the response pattern of signaling proteins and genes regulating protein synthesis and degradation in skeletal muscle after strength exercise sessions performed to volitional fatigue in strength-trained and untrained males. Eight healthy recreationally active males and 8 power-lifting athletes performed 4 sets of unilateral leg presses to exhaustion (65% 1 repetition maximum). Biopsy samples of m. vastus lateralis were obtained before, 1 and 5 hours after cessation of exercise. Phosphorylation of p70S6k, 4EBP1, and ACC increased, whereas phosphorylation of eEF2 and FOXO1 decreased only in the trained group after exercise. Expression of DDIT4, MURF1, and FOXO1 mRNAs increased and expression of MSTN mRNA decreased also only in the trained group after exercise. In conclusion, moderate-intensity strength exercise performed to volitional fatigue changed the phosphorylation status of mTORC1 downstream signaling molecules and markers of ubiquitin-proteasome system activation in trained individuals, suggesting activation of protein synthesis and degradation. In contrast to the trained group, signaling responses in the untrained group were considerably less pronounced. It can be assumed that the slowdown in muscle mass gain as the athletes increase in qualification cannot be associated with a decrease in the sensitivity of systems regulating protein metabolism, but possibly with inadequate intake or assimilation of nutrients necessary for anabolism. Perhaps, the intake of highly digestible protein or protein-carbohydrate dietary supplements could contribute to the increase in muscle mass in strength athletes.
列先科，EA，波波夫，DV，韦普卡瓦泽，TF，沙拉瓦，AP，和维诺格拉多娃，OL。中等强度力量训练至力竭导致力量训练个体的骨骼肌信号变化更为明显，与未经训练个体相比。J 力量与调理研究 34(4)：1103-1112，2020-我们的研究目的是比较在力量训练和未经训练的男性中，进行至力竭的力量运动后，调节蛋白质合成和降解的信号蛋白和基因的反应模式。8 名健康的娱乐性活跃男性和 8 名举重运动员进行了 4 组单侧腿举至力竭（65%1 次最大重复）。在运动停止前、1 小时和 5 小时后，从股外侧肌获得活检样本。p70S6k、4EBP1 和 ACC 的磷酸化增加，而 eEF2 和 FOXO1 的磷酸化仅在训练组中在运动后减少。DDIT4、MURF1 和 FOXO1 mRNA 的表达增加，MSTN mRNA 的表达在运动后也仅在训练组中减少。总之，中等强度的力量训练至力竭改变了 mTORC1 下游信号分子和泛素蛋白酶体系统激活标志物在训练个体中的磷酸化状态，提示蛋白质合成和降解的激活。与训练组相比，未经训练组的信号反应明显不那么明显。可以假设，随着运动员提高资格，肌肉质量增加的放缓不能与调节蛋白质代谢的系统敏感性降低相关，而可能与同化必要的营养素不足有关。也许，摄入易消化的蛋白质或蛋白质-碳水化合物膳食补充剂可以有助于增加力量运动员的肌肉质量。
