Reliability and sensitivity to change of post-match physical performance measures in elite youth soccer players

Alberto Franceschi; Mark A Robinson; Daniel Owens; Thomas Brownlee; Duccio Ferrari Bravo; Kevin Enright

doi:10.3389/fspor.2023.1173621

Reliability and sensitivity to change of post-match physical performance measures in elite youth soccer players

Front Sports Act Living. 2023 Jul 13:5:1173621. doi: 10.3389/fspor.2023.1173621. eCollection 2023.

Authors

Alberto Franceschi^{1

2}, Mark A Robinson², Daniel Owens², Thomas Brownlee³, Duccio Ferrari Bravo¹, Kevin Enright²

Affiliations

¹ Sport Science and R&D Department, Juventus Football Club, Torino, Italy.
² School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
³ School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.

Abstract

Introduction: To effectively monitor post-match changes in physical performance, valid, reliable and practical measures which are sensitive to change are required. This study aimed to quantify test-retest reliability and sensitivity to change of a range of physical performance measures recorded during an isometric posterior chain (IPC) lower-limb muscle test and a countermovement jump (CMJ) test.

Methods: Eighteen Italian Serie A academy soccer players performed three IPC repetitions per limb and five CMJ trials in 4 testing sessions. Test-retest reliability was evaluated between two testing sessions seven days apart using typical error of measurement, coefficient of variation and intraclass correlation coefficient. Sensitivity to change was assessed on two additional testing sessions performed before and immediately after a soccer match through Hedges' g effect size (g) and comparisons to typical error.

Results: Absolute reliability (coefficient of variations) ranged from 1.5 to 8.8%. IPC and CMJ measures demonstrated moderate to excellent relative reliability (intraclass correlation coefficients ranged from 0.70 to 0.98). A wide range of physical performance measures showed significant alterations post-match (p < 0.05; g: small to moderate). IPC peak force and torque, CMJ reactive strength index modified, CMJ eccentric forces (mean breaking force, mean deceleration force, peak force, force at zero velocity) and CMJ mean power measures had post-match changes greater than their typical variation, demonstrating acceptable sensitivity in detecting performance changes at post-match.

Discussion: IPC peak force and torque, CMJ reactive strength index modified, CMJ eccentric phase forces and CMJ mean power were found to be both reliable and sensitive to change, and thus may be appropriate for monitoring post-match neuromuscular performance in youth soccer population.

Keywords: football; monitoring; neuromuscular fatigue; recovery; reliability; responsiveness.