Corticomotor plasticity following unilateral strength training.
BACKGROUND
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.
Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia.
Alicia M
AM
Goodwill
Alan J
AJ
Pearce
Dawson J
DJ
Kidgell
D000222:Adaptation, Physiological / Q000502:physiology; D000293:Adolescent; D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D055070:Resistance Training; D050781:Transcranial Magnetic Stimulation