Prevalence of the Relative Age Effect in Spanish Orienteering: An Analysis by Sex and Competitive Level

This study investigates the relative age effect (RAE) in Spanish orienteering, comparing birth distributions between the general population and federated athletes, as well as across different age groups. A cross-sectional and retrospective observational analysis was conducted on data from 34,718 athletes federated (female: n = 12,338; male: n = 22,380) with the Spanish Orienteering Federation (FEDO) between 2005 and 2023. Birth distributions by quartiles and semesters were compared with birth data from the Spanish National Institute of Statistics. Chi-square tests, Z-tests for proportions, and odds ratio (OR) analysis were used to assess differences and the magnitude of the RAE. A significant RAE was found in the total population of federated athletes and the youth and male elite subgroups, with an over-representation of athletes born in the first semester of the year. The effect was small in magnitude but persistent in youth categories and intensified in the male elite category. In contrast, no significant RAE was observed in the female elite category. The RAE exists in Spanish orienteering, although its magnitude is smaller compared to other sports. The persistence of the RAE in the male elite category suggests that advantages accumulated in formative stages influence access to higher levels. Strategies to mitigate the impact of the RAE in talent identification and development are recommended.