A1 Journal article (refereed)
Strength‐trained adults demonstrate greater corticoreticular activation versus untrained controls (2024)

Akalu, Y., Tallent, J., Frazer, A. K., Siddique, U., Rostami, M., Vallance, P., Howatson, G., Walker, S., & Kidgell, D. J. (2024). Strength‐trained adults demonstrate greater corticoreticular activation versus untrained controls. European Journal of Neuroscience, 59(9), 2336-2352. https://doi.org/10.1111/ejn.16297

JYU authors or editors

Walker, Simon

Publication details

All authors or editors: Akalu, Yonas; Tallent, Jamie; Frazer, Ashlyn K.; Siddique, Ummatul; Rostami, Mohamad; Vallance, Patrick; Howatson, Glyn; Walker, Simon; Kidgell, Dawson J.

Journal or series: European Journal of Neuroscience

ISSN: 0953-816X

eISSN: 1460-9568

Publication year: 2024

Publication date: 28/02/2024

Volume: 59

Issue number: 9

Pages range: 2336-2352

Publisher: John Wiley & Sons

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1111/ejn.16297

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/94009

Abstract

The rapid increase in strength following strength-training involves neural adaptations, however, their specific localisation remains elusive. Prior focus on corticospinal responses prompts this study to explore the understudied cortical/subcortical adaptations, particularly cortico-reticulospinal tract responses, comparing healthy strength-trained adults to untrained peers. Fifteen chronically strength-trained individuals (≥2 years of training, mean age: 24 ± 7 years) were compared with 11 age-matched untrained participants (mean age:26 ± 8 years). Assessments included maximal voluntary force (MVF), corticospinal excitability using transcranial magnetic stimulation (TMS), spinal excitability (cervicomedullary stimulation), voluntary activation (VA) and reticulospinaltract (RST) excitability, utilizing Start React responses and ipsilateral motor-evoked potentials (iMEPs) for the flexor carpi radialis muscle. Trained participants had higher normalized MVF (6.4 ± 1.1 N/kg) than the untrained participants (4.8 ± 1.3 N/kg) (p=.003). Intracortical facilitation was higher in the strength-trained group (156 ± 49%) (p=.02), along with greater VA (98± 3.2%) (p=.002). The strength-trained group displayed reduced short-interval-intracortical inhibition (88 ± 8.0%) compared with the untrained group (69 ± 17.5%) (p< .001). Strength-trained individuals exhibited a greater normalized rate of force development (38.8 ± 10.1 Ns1/kg) (p< .009), greater reticulospinal gain (2.5 ± 1.4) (p=.02) and higher ipsilateral-to-contralateral MEPratios compared with the untrained group (p=.03). Strength-trained individuals displayed greater excitability within the intrinsic connections of the primary motor cortex and the RST. These results suggest greater synaptic input from the descending cortico-reticulospinal tract toα-motoneurons in strength-trained individuals, thereby contributing to the observed increase in VA and MVF.

Keywords: transcranial magnetic stimulation; strength training; training; physical training

Free keywords: reticulospinal tract; StartReact protocol; strength-training; transcranial magnetic stimulation

Fields of science: