This study determined whether there are task-dependent differences in cortical excitability following different types of strength training. Transcranial magnetic stimulation (TMS) measured corticospinal excitability (CSE) and intracortical inhibition (ICI) of the biceps brachii muscle in 42 healthy subjects that were randomised to either paced-strength-training (PST, n = 11), self-paced strength-training (SPST, n = 11), isometric strength-training (IST, n = 10) or to a control group (n = 10). Single-pulse and paired-pulse TMS were applied prior to and following 4-weeks of strength-training. PST increased CSE compared to SPST, IST and the control group (all P < 0.05). ICI was only reduced (60%) following PST. Dynamic strength increased by 18 and 25% following PST and SPST, whilst isometric strength increased by 20% following IST. There were no associations between the behavioural outcome measures and the change in CSE and ICI. The corticospinal responses to strength-training are task-dependent, which is a new finding. Strength-training that is performed slowly could promote use-dependent plasticity in populations with reduced volitional drive, such as during periods of limb immobilization, musculoskeletal injury or stroke.

中文翻译：

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强度训练后，取决于任务的皮质脊髓兴奋性调节和抑制作用。

这项研究确定了不同类型的力量训练后，皮层兴奋性是否存在任务相关的差异。经颅磁刺激（TMS）在42位健康受试者中测量了肱二头肌肱二头肌的皮质脊髓兴奋性（CSE）和皮质内抑制（ICI），这些受试者被随机分为步速训练（PST，n = 11），自定速度强度-训练（SPST，n = 11），等距力量训练（IST，n = 10）或对照组（n = 10）。在进行4周的力量训练之前和之后应用单脉冲和成对脉冲TMS。与SPST，IST和对照组相比，PST增加了CSE（所有P <0.05）。PST后，ICI仅降低了（60％）。在PST和SPST之后，动态强度增加了18％和25％，而在IST之后，等距强度增加了20％。行为结果指标与CSE和ICI的变化之间没有关联。皮质脊髓对力量训练的反应取决于任务，这是一个新发现。缓慢进行的力量训练可以在意志力减弱的人群中提高依赖用途的可塑性，例如在肢体固定，肌肉骨骼损伤或中风期间。