Relative age effects in Scottish male under 16 national players: The presence and effects on selection into an under 17 national squad

The Relative Age Effect (RAE) is characterised by the difficulties faced by relatively younger individuals due to differences in chronological age (CA) and the related physical and maturational factors that occur in annual age grouped cohorts. This study investigated the presence of RAE within Scottish Rugby Union’s (SRU) Academy, identified if physiological and performance measures could distinguish between players born in the first and last quarters of the selection year, Quartile 1 (Q1) and Quartile 4 (Q4), and tracked RAE post selection.

Birth dates, physiological and performance measures (countermovement jump, 40m sprint and YoYo Intermittent Recovery Test) were collected from 50 male Under 16 (U16) Rugby players (mean ± SD age 15.6 ± 0.3 years, height 181.1 ± 6.8cm, body mass 79.3 ± 13.1kg) with Maturation and Momentum calculated post testing. Chi-Square Analysis (X²) compared squad distribution to National Births, Odds Ratio (OR) Tests compared the odds of Q4 selection to all other quartiles. One-way Independent ANOVA and Tukey Post-Hoc Tests identified differences in physiological and performance measures between quartiles and an Independent Samples T Test distinguished differences between players graduating to Under 17 (U17) and those released. A RAE was found in the U16 (X² = 9.154, p=0.027) but not in the U17 (X²=2.122, p=0.548) squad, no significant ORs, physiological or performance measures were found that could distinguish between Q1 and Q4, (p> 0.05). The T-test found that the graduating players had greater Momentum over 0-10m (p=0.012), 10-20m (p=0.015), 30-40m (p=0.010) than those released. Given there is no finding to suggest that RAE is correlated to physiological or performance measures, National Governing Bodies and Talent ID coaches should consider prioritising maturation specific monitoring.