Corticomotor plasticity following unilateral strength training

Muscle Nerve. 2012 Sep;46(3):384-93. doi: 10.1002/mus.23316.


Introduction: We used transcranial magnetic stimulation (TMS) to investigate 3 weeks of unilateral leg strength training on ipsilateral motor cortex (iM1) excitability, and short-latency intracortical inhibition (SICI).

Methods: Right leg dominant participants (n = 14) were randomly divided into either a strength training (ST) or control group. The ST group completed 9 training sessions (4 sets of 6 to 8 repetitions of single right leg squats).

Results: We observed a 41% increase in right leg strength, and a 35% increase in strength of the untrained left leg (P < 0.01). There was a significant increase in motor evoked potential (MEP) amplitude recruitment curve for the untrained left leg (P < 0.01). SICI of the iM1 decreased by 21% for the untrained left leg (P < 0.01).

Conclusions: The findings provide evidence for corticomotor adaptation for unilateral leg strength training within the iM1 that is modulated by changes in interhemispheric inhibition.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adaptation, Physiological / physiology
  • Adolescent
  • Adult
  • Electromyography
  • Evoked Potentials, Motor / physiology*
  • Female
  • Functional Laterality / physiology*
  • Humans
  • Leg / physiology
  • Male
  • Motor Cortex / physiology*
  • Muscle Strength / physiology*
  • Muscle, Skeletal / physiology*
  • Neuronal Plasticity / physiology*
  • Neurons / physiology
  • Resistance Training*
  • Transcranial Magnetic Stimulation