Modulation of intracortical inhibition and excitation in agonist and antagonist muscles following acute strength training

Joel Mason, Glyn Howatson, Ashlyn K. Frazer, Alan J. Pearce, Shapour Jaberzadeh, Janne Avela, Dawson J. Kidgell

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Purpose: Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (dominant-arm only) to identify the early antagonistic responses to a single session that may accompany improvements in strength. Methods: Corticospinal and motor cortical excitability and inhibition was collected from agonist and antagonist muscles prior to and following a single session of heavy-loaded wrist flexor training in 18 individuals. Training consisted of four sets 6–8 repetitions at 80% of 1-repetition maximum (1-RM). Recruitment curves for corticospinal excitability and inhibition of the right wrist flexor and wrist extensor muscles were constructed and assessed by examining the area under the recruitment curve. Intracortical measures were obtained using paired-pulse TMS. Results: Following a single training session, increases in corticospinal excitability were observed in both the agonist and antagonist muscles. This was accompanied by decreases in corticospinal inhibition in both muscles. Intracortical inhibition was reduced and intracortical facilitation was increased for the agonist muscle only. Intracortical measures in the antagonist muscle remained unchanged after training. Conclusions: These findings indicate that the corticospinal responses to a single session of strength training are similar between agonist and antagonist muscles, but the intrinsic cortico-cortical circuitry of the antagonist remains unchanged. The corticospinal responses are likely due to increased involvement/co-activation of the antagonist muscle during training as the agonist muscle fatigues.

Original languageEnglish
Number of pages15
JournalEuropean Journal of Applied Physiology
DOIs
Publication statusAccepted/In press - 5 Aug 2019

Keywords

  • Agonist
  • Antagonist
  • Corticospinal excitability
  • Corticospinal silent period
  • Intracortical facilitation
  • Short-interval cortical inhibition
  • Strength training

Cite this

@article{c49cf8698fe841788ec30903170b6629,
title = "Modulation of intracortical inhibition and excitation in agonist and antagonist muscles following acute strength training",
abstract = "Purpose: Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (dominant-arm only) to identify the early antagonistic responses to a single session that may accompany improvements in strength. Methods: Corticospinal and motor cortical excitability and inhibition was collected from agonist and antagonist muscles prior to and following a single session of heavy-loaded wrist flexor training in 18 individuals. Training consisted of four sets 6–8 repetitions at 80{\%} of 1-repetition maximum (1-RM). Recruitment curves for corticospinal excitability and inhibition of the right wrist flexor and wrist extensor muscles were constructed and assessed by examining the area under the recruitment curve. Intracortical measures were obtained using paired-pulse TMS. Results: Following a single training session, increases in corticospinal excitability were observed in both the agonist and antagonist muscles. This was accompanied by decreases in corticospinal inhibition in both muscles. Intracortical inhibition was reduced and intracortical facilitation was increased for the agonist muscle only. Intracortical measures in the antagonist muscle remained unchanged after training. Conclusions: These findings indicate that the corticospinal responses to a single session of strength training are similar between agonist and antagonist muscles, but the intrinsic cortico-cortical circuitry of the antagonist remains unchanged. The corticospinal responses are likely due to increased involvement/co-activation of the antagonist muscle during training as the agonist muscle fatigues.",
keywords = "Agonist, Antagonist, Corticospinal excitability, Corticospinal silent period, Intracortical facilitation, Short-interval cortical inhibition, Strength training",
author = "Joel Mason and Glyn Howatson and Frazer, {Ashlyn K.} and Pearce, {Alan J.} and Shapour Jaberzadeh and Janne Avela and Kidgell, {Dawson J.}",
year = "2019",
month = "8",
day = "5",
doi = "10.1007/s00421-019-04203-9",
language = "English",
journal = "European Journal of Applied Physiology",
issn = "1439-6319",
publisher = "Springer-Verlag London Ltd.",

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Modulation of intracortical inhibition and excitation in agonist and antagonist muscles following acute strength training. / Mason, Joel; Howatson, Glyn; Frazer, Ashlyn K.; Pearce, Alan J.; Jaberzadeh, Shapour; Avela, Janne; Kidgell, Dawson J.

In: European Journal of Applied Physiology, 05.08.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Modulation of intracortical inhibition and excitation in agonist and antagonist muscles following acute strength training

AU - Mason, Joel

AU - Howatson, Glyn

AU - Frazer, Ashlyn K.

AU - Pearce, Alan J.

AU - Jaberzadeh, Shapour

AU - Avela, Janne

AU - Kidgell, Dawson J.

PY - 2019/8/5

Y1 - 2019/8/5

N2 - Purpose: Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (dominant-arm only) to identify the early antagonistic responses to a single session that may accompany improvements in strength. Methods: Corticospinal and motor cortical excitability and inhibition was collected from agonist and antagonist muscles prior to and following a single session of heavy-loaded wrist flexor training in 18 individuals. Training consisted of four sets 6–8 repetitions at 80% of 1-repetition maximum (1-RM). Recruitment curves for corticospinal excitability and inhibition of the right wrist flexor and wrist extensor muscles were constructed and assessed by examining the area under the recruitment curve. Intracortical measures were obtained using paired-pulse TMS. Results: Following a single training session, increases in corticospinal excitability were observed in both the agonist and antagonist muscles. This was accompanied by decreases in corticospinal inhibition in both muscles. Intracortical inhibition was reduced and intracortical facilitation was increased for the agonist muscle only. Intracortical measures in the antagonist muscle remained unchanged after training. Conclusions: These findings indicate that the corticospinal responses to a single session of strength training are similar between agonist and antagonist muscles, but the intrinsic cortico-cortical circuitry of the antagonist remains unchanged. The corticospinal responses are likely due to increased involvement/co-activation of the antagonist muscle during training as the agonist muscle fatigues.

AB - Purpose: Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (dominant-arm only) to identify the early antagonistic responses to a single session that may accompany improvements in strength. Methods: Corticospinal and motor cortical excitability and inhibition was collected from agonist and antagonist muscles prior to and following a single session of heavy-loaded wrist flexor training in 18 individuals. Training consisted of four sets 6–8 repetitions at 80% of 1-repetition maximum (1-RM). Recruitment curves for corticospinal excitability and inhibition of the right wrist flexor and wrist extensor muscles were constructed and assessed by examining the area under the recruitment curve. Intracortical measures were obtained using paired-pulse TMS. Results: Following a single training session, increases in corticospinal excitability were observed in both the agonist and antagonist muscles. This was accompanied by decreases in corticospinal inhibition in both muscles. Intracortical inhibition was reduced and intracortical facilitation was increased for the agonist muscle only. Intracortical measures in the antagonist muscle remained unchanged after training. Conclusions: These findings indicate that the corticospinal responses to a single session of strength training are similar between agonist and antagonist muscles, but the intrinsic cortico-cortical circuitry of the antagonist remains unchanged. The corticospinal responses are likely due to increased involvement/co-activation of the antagonist muscle during training as the agonist muscle fatigues.

KW - Agonist

KW - Antagonist

KW - Corticospinal excitability

KW - Corticospinal silent period

KW - Intracortical facilitation

KW - Short-interval cortical inhibition

KW - Strength training

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U2 - 10.1007/s00421-019-04203-9

DO - 10.1007/s00421-019-04203-9

M3 - Article

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

ER -