Discipline of Physiology, School of Biomedicine, The University of Adelaide, Adelaide, South Australia, Australia.
J Appl Physiol (1985). 2022 Oct 1;133(4):932-944. doi: 10.1152/japplphysiol.00213.2022. Epub 2022 Sep 8.
Previous research using transcranial magnetic stimulation (TMS) has shown that plasticity within primary motor cortex (M1) is greater in people who undertake regular exercise, and a single session of aerobic exercise can increase M1 plasticity in untrained participants. This study aimed to examine the effect of an acute bout of exercise on M1 plasticity in endurance-trained (cyclists) and untrained individuals. Fourteen endurance-trained cyclists (mean ± SD; 23 ± 3.8 yr) and 14 untrained individuals (22 ± 1.8 yr) performed two experimental sessions. One session included an acute bout of high-intensity interval training (HIIT) exercise involving stationary cycling, whereas another session involved no-exercise (control). Following exercise (or control), I-wave periodicity repetitive TMS (iTMS) was used (1.5-ms interval, 180 pairs) to induce plasticity within M1. Motor evoked potentials (MEPs) induced by single and paired-pulse TMS over M1 were recorded from a hand muscle at baseline, after HIIT (or control) exercise and after iTMS. Corticospinal and intracortical excitability was not influenced by HIIT exercise in either group (all > 0.05). There was an increase in MEP amplitude after iTMS, and this was greater after HIIT exercise (compared with control) for all subjects ( < 0.001). However, the magnitude of this response was larger in endurance cyclists compared with the untrained group ( = 0.049). These findings indicate that M1 plasticity induced by iTMS was greater in endurance-trained cyclists following HIIT. Prior history of exercise training is, therefore, an important consideration for understanding factors that contribute to exercise-induced plasticity. We use a novel form of repetitive transcranial magnetic stimulation to show that motor cortex plasticity is increased after acute exercise and that this effect is bolstered in endurance-trained cyclists. These findings indicate that participation in regular endurance exercise (involving lower limb muscles) has widespread effects on cortical plasticity (assessed in unexercised upper limb muscles) following acute lower-limb cycling exercise. It also highlights that exercise history is an important factor in exercise-induced cortical plasticity.
先前使用经颅磁刺激（TMS）的研究表明，经常运动的人初级运动皮层（M1）的可塑性更大，单次有氧运动可以增加未经训练的参与者的 M1 可塑性。本研究旨在检查急性运动对耐力训练（自行车运动员）和未经训练个体的 M1 可塑性的影响。14 名耐力训练的自行车运动员（均值±标准差；23±3.8 岁）和 14 名未经训练的个体（22±1.8 岁）进行了两次实验。一次实验包括高强度间歇训练（HIIT）运动，涉及固定自行车，而另一次实验则不进行运动（对照组）。运动（或对照组）后，使用 I 波周期性重复 TMS（iTMS）（1.5ms 间隔，180 对）诱导 M1 内的可塑性。在基线、HIIT（或对照组）运动后和 iTMS 后，从手部肌肉记录 M1 上单脉冲和双脉冲 TMS 诱导的运动诱发电位（MEP）。HIIT 运动对两组的皮质脊髓和皮质内兴奋性均无影响（均>0.05）。iTMS 后 MEP 振幅增加，与对照组相比，HIIT 运动后（所有受试者）增加更大（<0.001）。然而，与未经训练组相比，耐力自行车运动员的这种反应幅度更大（=0.049）。这些发现表明，HIIT 后，iTMS 诱导的 M1 可塑性在耐力训练的自行车运动员中更大。因此，既往运动训练史是理解促进运动诱导可塑性的因素的重要考虑因素。我们使用一种新形式的重复经颅磁刺激来表明，运动皮层的可塑性在急性运动后增加，并且这种效应在耐力训练的自行车运动员中得到增强。这些发现表明，经常进行耐力运动（涉及下肢肌肉）会对急性下肢自行车运动后未运动的上肢肌肉的皮质可塑性产生广泛影响。它还强调了运动史是运动诱导皮质可塑性的一个重要因素。
