Balshaw Thomas G, Massey Garry J, Maden-Wilkinson Thomas M, Morales-Artacho Antonio J, McKeown Alexandra, Appleby Clare L, Folland Jonathan P
Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis, Loughborough University, Leicestershire, UK.
School of Sport, Exercise, and Health Sciences, Loughborough University, Leicestershire, LE11 3TU, UK.
Eur J Appl Physiol. 2017 Apr;117(4):631-640. doi: 10.1007/s00421-017-3560-x. Epub 2017 Feb 26.
Whilst neural and morphological adaptations following resistance training (RT) have been investigated extensively at a group level, relatively little is known about the contribution of specific physiological mechanisms, or pre-training strength, to the individual changes in strength following training. This study investigated the contribution of multiple underpinning neural [agonist EMG (QEMG), antagonist EMG (HEMG)] and morphological variables [total quadriceps volume (QUADS), and muscle fascicle pennation angle (QUADSθ )], as well as pre-training strength, to the individual changes in strength after 12 weeks of knee extensor RT.
Twenty-eight healthy young men completed 12 weeks of isometric knee extensor RT (3/week). Isometric maximum voluntary torque (MVT) was assessed pre- and post-RT, as were simultaneous neural drive to the agonist (QEMG) and antagonist (HEMG). In addition QUADS was determined with MRI and QUADSθ with B-mode ultrasound.
Percentage changes (∆) in MVT were correlated to ∆QEMG (r = 0.576, P = 0.001), ∆QUADS (r = 0.461, P = 0.014), and pre-training MVT (r = -0.429, P = 0.023), but not ∆HEMG (r = 0.298, P = 0.123) or ∆QUADSθ (r = -0.207, P = 0.291). Multiple regression analysis revealed 59.9% of the total variance in ∆MVT after RT to be explained by ∆QEMG (30.6%), ∆QUADS (18.7%), and pre-training MVT (10.6%).
Changes in agonist neural drive, quadriceps muscle volume and pre-training strength combined to explain the majority of the variance in strength changes after knee extensor RT (~60%) and adaptations in agonist neural drive were the most important single predictor during this short-term intervention.
虽然在群体水平上对阻力训练（RT）后的神经和形态学适应进行了广泛研究，但对于特定生理机制或训练前力量对训练后个体力量变化的贡献知之甚少。本研究调查了多种潜在的神经变量[主动肌肌电图（QEMG）、拮抗肌肌电图（HEMG）]和形态学变量[股四头肌总体积（QUADS）和肌肉束羽状角（QUADSθ）]，以及训练前力量对膝关节伸肌RT 12周后个体力量变化的贡献。
28名健康年轻男性完成了12周的等长膝关节伸肌RT（每周3次）。在RT前后评估等长最大自主扭矩（MVT），同时评估对主动肌（QEMG）和拮抗肌（HEMG）的神经驱动。此外，用MRI测定QUADS，用B型超声测定QUADSθ。
MVT的百分比变化（∆）与∆QEMG（r = 0.576，P = 0.001）、∆QUADS（r = 0.461，P = 0.014）和训练前MVT（r = -0.429，P = 0.023）相关，但与∆HEMG（r = 0.298，P = 0.123）或∆QUADSθ（r = -0.207，P = 0.291）无关。多元回归分析显示，RT后∆MVT总方差的59.9%可由∆QEMG（30.6%）、∆QUADS（18.7%）和训练前MVT（10.6%）解释。
主动肌神经驱动、股四头肌体积和训练前力量的变化共同解释了膝关节伸肌RT后力量变化的大部分方差（约60%），在这种短期干预中，主动肌神经驱动的适应是最重要的单一预测因素。
