Abstract
This study evaluates the contributions of age, skeletal maturation, body size and
composition, training and playing position to the development of agility and dribbling
speed in young male soccer players (10–18 years) followed longitudinally. 83 players
[defenders (n=35), midfielders (n=27), forwards (n=21)] were followed annually over 5 years (average: 4.4 observations per player).
Skeletal age (SA), stature, body mass, triceps and subscapular skinfolds, agility
and dribbling speed were measured annually. Body composition was estimated from the
2 skinfolds. Annual training volume was estimated from weekly participation forms
completed by coaches. The multiplicative allometric models with the best statistical
fit showed that statural growth of 1 cm predicts 1.334 s and 1.927 s of improvement
in agility and dribbling speed, respectively. Significant independent effects of fat-free
mass and annual volume training were found for agility and dribbling speed, respectively
(P<0.05). Predicted agility (from 12 to 18 years of SA) and dribbling speed (from 13
to 18 years of SA) differed significantly among players by playing positions (midfielders>forwards>defenders).
The present results provide developmental models for the interpretation of intra-
and inter-individual variability in agility and dribbling speed among youth soccer
players across adolescence, and may provide a framework for trainers and coaches to
develop and evaluate individualized training protocols.
Key words
youth sport - adolescence - longitudinal analysis - allometry - maturation - skills
