Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences, School of Primary and Allied Health Care, Monash University, PO Box 527, Frankston, VIC, 3199, Australia.
Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK.
Eur J Appl Physiol. 2019 Oct;119(10):2185-2199. doi: 10.1007/s00421-019-04203-9. Epub 2019 Aug 5.
Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (dominant-arm only) to identify the early antagonistic responses to a single session that may accompany improvements in strength.
Corticospinal and motor cortical excitability and inhibition was collected from agonist and antagonist muscles prior to and following a single session of heavy-loaded wrist flexor training in 18 individuals. Training consisted of four sets 6-8 repetitions at 80% of 1-repetition maximum (1-RM). Recruitment curves for corticospinal excitability and inhibition of the right wrist flexor and wrist extensor muscles were constructed and assessed by examining the area under the recruitment curve. Intracortical measures were obtained using paired-pulse TMS.
Following a single training session, increases in corticospinal excitability were observed in both the agonist and antagonist muscles. This was accompanied by decreases in corticospinal inhibition in both muscles. Intracortical inhibition was reduced and intracortical facilitation was increased for the agonist muscle only. Intracortical measures in the antagonist muscle remained unchanged after training.
These findings indicate that the corticospinal responses to a single session of strength training are similar between agonist and antagonist muscles, but the intrinsic cortico-cortical circuitry of the antagonist remains unchanged. The corticospinal responses are likely due to increased involvement/co-activation of the antagonist muscle during training as the agonist muscle fatigues.
经颅磁刺激（TMS）通常研究的是运动皮质反应的激动剂肌肉力量训练，尽管拮抗剂肌肉在力量发展中的作用。我们研究了从一个激动剂和拮抗剂肌肉的皮质内反应后，只有单一的会话重载力量训练（优势臂），以确定早期拮抗反应，以一个单一的会议，可能伴随着力量的提高。
皮质脊髓兴奋性和运动皮质兴奋性和抑制性从激动剂和拮抗剂肌肉收集之前和之后的单一会话重载腕屈肌训练在 18 个人。训练包括四个集 6-8 重复在 80%的 1 重复最大（1-RM）。皮质脊髓兴奋性和抑制性的募集曲线的右腕屈肌和腕伸肌肌肉构建和评估检查募集曲线下面积。皮质内测量使用配对脉冲 TMS。
经过一次训练后，在激动剂和拮抗剂肌肉中都观察到皮质脊髓兴奋性的增加。这伴随着在两种肌肉中皮质脊髓抑制的减少。在激动剂肌肉中，皮质内抑制减少，皮质内易化增加。拮抗剂肌肉的皮质内测量在训练后保持不变。
这些发现表明，单一的力量训练会话的皮质脊髓反应在激动剂和拮抗剂肌肉之间是相似的，但拮抗剂的固有皮质-皮质电路保持不变。皮质脊髓反应可能是由于在训练过程中拮抗剂肌肉的参与/协同激活增加，而激动剂肌肉疲劳。
