Changes in corticomotor excitability after fatiguing muscle contractions. Academic Article uri icon

Overview

abstract

  • To investigate whether the type and duration of activity influences corticomotor excitability following fatiguing exercise, we compared motor evoked potential (MEP) responses of the biceps brachii to transcranial magnetic stimulation (TMS) during recovery from two different exercise regimens. Responses were recorded in both the resting state and during a weak contraction. Ten subjects performed a 60-s maximal voluntary contraction (MVC) and, on a subsequent occasion, a sustained 20% MVC to the point of exhaustion. Resting MEP amplitude declined following maximal and submaximal protocols, reaching 34% and 31% of pre-exercise means, respectively (P < 0.001 for both). In contrast, mean facilitated MEP amplitude showed a smaller and more transient decrement following the sustained submaximal effort (64%; P < 0.05), but not the 60-s MVC. Abolition of the postexercise depression in resting MEP amplitude by a weak tonic contraction indicates that decreases in excitability at the spinal level contribute to the reduced corticomotor excitability observed after fatiguing exercise.

publication date

  • December 1, 2000

Research

keywords

  • Brain
  • Evoked Potentials, Motor
  • Isometric Contraction
  • Muscle Fatigue
  • Muscle, Skeletal
  • Physical Exertion

Identity

Scopus Document Identifier

  • 0033653691

Digital Object Identifier (DOI)

  • 10.1002/1097-4598(200012)23:12<1840::aid-mus7>3.0.co;2-h

PubMed ID

  • 11102907

Additional Document Info

volume

  • 23

issue

  • 12