The stability of youth soccer players' performance characteristics after an 18-month development period

Introduction and Aims: Sporting organisations commonly adopt an early identification approach to select youth athletes that display potential to excel within a sport. However, this approach assumes a direct relationship between youth and senior performance. The present study aimed to examine the stability of youth soccer players’ anthropometry, motor competence, physical fitness, and decision-making skill. Methods: Twenty-seven male soccer players from two age cohorts – early (12-13 yr, n=18) and mid-adolescence (14-15 yr, n=9) – were recruited from a high-level academy. A multifactorial assessment battery including anthropometry, motor competence, physical fitness, and decision-making was employed on two occasions 18-months apart. A multivariate analysis of variance assessed changes in players’ performance characteristic. Stability was examined using intraclass correlation coefficients. Results: Early and mid-adolescence players presented similar changes in their performance characteristics over 18 months (F=1.66, p=0.20, ƞ2=0.63). The early adolescence group’s stability was classified as: very low – balancing backwards and jumping sideways; low – jumping sideways, 5 m sprint, Yo-Yo, decision-making accuracy, and decision-making response time; moderate – vertical jump and T-Test; high – 30 m sprint; and very high – stature and body mass. The mid adolescence group stability’s was classified as low – balancing backwards; moderate – vertical jump, 5 m sprint, T-Test, Yo-Yo, and decision-making accuracy; high – moving sideways, jumping sideways, and 30 m sprint; and very high – stature, body mass, decision-making response time. Conclusion: This study demonstrates the instability of players’ performance characteristics during development. Although mid-adolescence players show greater stability when compared with their younger counterparts, it is imperative that talent identification programs collect longitudinal data when determining a players’ potential for future success.