Longitudinal development of muscle strength and relationship with motor unit activity and muscle morphological characteristics in youth athletes.
Exp Brain Res
; 241(4): 1009-1019, 2023 Apr.
Article
em En
| MEDLINE
| ID: mdl-36905448
ABSTRACT
Neural and morphological adaptations determine gains of muscle strength. For youth athletes, the importance of morphological adaptation is typically highlighted based on the change in maturity status. However, the long-term development of neural components in youth athletes remains unclear. The present study investigated the longitudinal development of muscle strength, muscle thickness (MT), and motor unit firing activity of the knee extensor and their relationships in youth athletes. Seventy male youth soccer players (mean ± SD age = 16.3 ± 0.6 years) performed neuromuscular, maximal voluntary isometric contraction (MVC), and submaximal ramp contraction (at 30 and 50% MVC) tests with knee extensors, two times with a 10-month measurement interval. High-density surface electromyography was recorded from the vastus lateralis and decomposed to identify each individual motor unit activity. MT was evaluated by the sum of the vastus lateralis and vastus intermedius thicknesses. Finally, sixty-four participants were employed to compare MVC and MT, and 26 participants were employed to analyze motor unit activity. MVC and MT were increased from pre to post (p < 0.05, 6.9 and 1.7% for MVC and MT, respectively). Y-intercept of the regression line between median firing rate vs. recruitment threshold was also increased (p < 0.05, 13.3%). Multiple regression analysis demonstrated that the gains of both MT and Y-intercept were explanatory variables for the gain of strength. These findings suggest that the neural adaptation could also make the important contribution to the strength gain for the youth athletes over a 10-month training period.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Músculo Quadríceps
/
Força Muscular
Tipo de estudo:
Prognostic_studies
Limite:
Adolescent
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Humans
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Male
Idioma:
En
Revista:
Exp Brain Res
Ano de publicação:
2023
Tipo de documento:
Article