Soccer Player Characteristics in English Lower-League Development Programmes: The Relationships between Relative Age, Maturation, Anthropometry and Physical Fitness.

Ric Lovell,Roel Vaeyens,Guy Parkin,Stephen Cobley,Matt Portas,Chris Towlson,Alejandro Lucia

doi:10.1371/journal.pone.0137238

Abstract

The relative age effect (RAE) and its relationships with maturation, anthropometry, and physical performance characteristics were examined across a representative sample of English youth soccer development programmes. Birth dates of 1,212 players, chronologically age-grouped (i.e., U9’s-U18’s), representing 17 professional clubs (i.e., playing in Leagues 1 & 2) were obtained and categorised into relative age quartiles from the start of the selection year (Q1 = Sep-Nov; Q2 = Dec-Feb; Q3 = Mar-May; Q4 = Jun-Aug). Players were measured for somatic maturation and performed a battery of physical tests to determine aerobic fitness (Multi-Stage Fitness Test [MSFT]), Maximal Vertical Jump (MVJ), sprint (10 & 20m), and agility (T-Test) performance capabilities. Odds ratio’s (OR) revealed Q1 players were 5.3 times (95% confidence intervals [CI]: 4.08–6.83) more likely to be selected than Q4’s, with a particularly strong RAE bias observed in U9 (OR: 5.56) and U13-U16 squads (OR: 5.45–6.13). Multivariate statistical models identified few between quartile differences in anthropometric and fitness characteristics, and confirmed chronological age-group and estimated age at peak height velocity (APHV) as covariates. Assessment of practical significance using magnitude-based inferences demonstrated body size advantages in relatively older players (Q1 vs. Q4) that were very-likely small (Effect Size [ES]: 0.53–0.57), and likely to very-likely moderate (ES: 0.62–0.72) in U12 and U14 squads, respectively. Relatively older U12-U14 players also demonstrated small advantages in 10m (ES: 0.31–0.45) and 20m sprint performance (ES: 0.36–0.46). The data identify a strong RAE bias at the entry-point to English soccer developmental programmes. RAE was also stronger circa-PHV, and relatively older players demonstrated anaerobic performance advantages during the pubescent period. Talent selectors should consider motor function and maturation status assessments to avoid premature and unwarranted drop-out of soccer players within youth development programmes.

Highlights

The relative age effect (RAE) is a well-established phenomenon in team-sports such as Soccer [1,2,3,4]
The underlying causes of the RAE in a Soccer context have not been distinguished empirically, consensus implies that players born in the early months of the section year are likely at a physical advantage due to normative growth and/or biological maturation, and in the early stages of participation possess greater playing experience
An un-even distribution was identified for each annual group, with 36–56% of players born in Q1 and 7–16% in Q4

Summary

Introduction

The relative age effect (RAE) is a well-established phenomenon in team-sports such as Soccer [1,2,3,4]. The underlying causes of the RAE in a Soccer context have not been distinguished empirically, consensus implies that players born in the early months of the section year are likely at a physical advantage due to normative growth and/or biological maturation, and in the early stages of participation possess greater playing experience. This has been referred to as the maturation-selection hypothesis [2,7]. The growing concern for coaches and selectors is that skillful, but biologically delayed, soccer players may be lost in the early and developmental stages of athlete development

Objectives

Methods

Results