The role of a relative age effect in the first winter Youth Olympic Games in 2012

Abstract

Background: Owing to the separation into age groups at the first winter Youth Olympic Games (YOG), athletes differed in age by up to two years, leading to a potential relative age effect (RAE).

Objective: The purpose of this study was to define the role of the RAE in the first winter YOG with regard to sex, type of sport and performance.

Methods: The birth dates and anthropometric data of all 1021 athletes (557 male, 464 female, 14-19 years old) participating in 15 sports were analysed. A χ(2) test was used to assess the difference between the observed and expected birth distributions. ANOVA (analysis of variance) and Kruskal-Wallis analyses were used to investigate differences in anthropometrics.

Results: The birth date distribution of the overall sample was significantly different from an equal distribution, with an over-representation of athletes born shortly after the cut-off date (χ(2)=284.7, p<0.001). A significant RAE was found in both male (χ(2)=245.1, p<0.001) and female competitors (χ(2)=74.6, p<0.001). An analysis based on the type of sport showed an RAE in all categories (strength-χ(2)=229.9, p<0.001, endurance-χ(2)=60.4, p<0.001 and technique-related sports χ(2)=25.2, p=0.001). Relatively older competitors were also over-represented among medal winners (χ(2)=47.9, p<0.001). Relatively older male competitors were significantly taller (p=0.005) and heavier (p<0.001) than younger competitors. No differences were found in female competitors.

Conclusions: The results suggest that relative age had a highly significant influence on participation in various sports regardless of sex. A possible strategy to reduce the RAE would be a fixed quota for each birth year within the two-year age group across events.