The interaction of relative age with maturation and body size in female handball talent selection based on only sport-specific criteria

Talent identification is often affected by the relative age effects (RAEs) and/or maturation. Previous research has suggested that talent selection should include sport-specific technical tasks instead of body size and/or physical test measurements, assuming that the technical tasks are less influenced by interindividual variability in maturation. Our purpose was to examine the prevalence of RAEs and how biological maturity, body size, and body composition in relation to relative age affect talent selection among female handball players. Handball-specific drills and in-game performance were the criteria of a single talent selection program. Birth distribution of U14 female (N = 3198) handball players were analyzed. Body size, body composition, and bone age were assessed on 264 selected and 266 not-selected players. Body composition was assessed with InBody 720, whereas biological age from bone age. Chi-square was used to examine quartile distributions, and logistic regression to determine the effects of the predictors on the selection. In terms of all registered players, there was no difference in birth distribution. RAEs appeared at the first selection level and were evident at all levels. Quartiles differed only between the first and the last quartiles in body size and muscle mass. Only bone age differed between consecutive quartile or semi-year groups. Body size, body composition, and maturity had a significant, but of moderate power, effect on the selection. Larger body height increased selection odds by about 12%, larger muscle mass by 12% to 25%, larger percent body fat decreased selection odds by 7%, while larger bone age by 3.5-4 times. RAEs affected talent selection when applying sport-specific drills as selection criteria. Relative age was connected to bone age, but not convincingly to body size and muscle mass. Bone age had the largest effect on the selection, but this was not associated with larger body size or muscle mass.