Abstract
The aim of the study was to compare 3-year changes in physical performance between
junior soccer players selected for an elite academy and age-matched controls. The
3-year changes in indicators of the physical performance were quantified in 12–16-year-old
Premier League Academy (n=27) and non-academy soccer players (n=18). Data were analysed
with an age-group×competitive level general linear model, covariate-adjusted for initial
performance level and change in maturation. Covariate adjusted mean±SD changes were
greater (standardised effect size>0.7) for the academy players in terms of countermovement
jump (7.3±2.6 vs. 5.4±2.5 cm), 10 m sprint (− 0.15±0.05 vs. − 0.10±0.04 s), 20 m sprint
(− 0.30±0.16 s vs. − 0.15±0.13 s), agility (− 0.19±0.01 s vs. − 0.08±0.08 s), repeated
sprint (− 0.60±0.26 s vs. − 0.41±2.1 s) and intermittent endurance capacity (1 128±406
vs. 315±370 m). These data indicate that a 3-year programme of training in an elite
soccer academy is associated with greater changes in physical performance indicators
independently from the initial performance level of the child and change in maturation
over the same period of time.
Key words
adolescents - growth - longitudinal - performance