The influence of age category and relative age on match running performance at the men’s U17 and U20 World Cups

The aim of this study was to evaluate the influence of age category (AC) and relative age effects (RAEs) on the running performance of youth soccer players. We analysed matches from the men’s U17 (n = 47) and U20 (n = 50) World Cups. A total of 452 (U17 = 218; U20 = 234) soccer players who played 90 minutes in matches during each tournament were evaluated in order to analyse the impact of AC and RAEs on running performances obtained by multiple camera computerised optical tracking system (OTS) (TRACAB). Running performance included: total distance covered (m), distance in the speed categories of Zone1,2,3,4,5 (m), attempted high-speed runs (count), attempted sprint (count), and top speed (km·h−1). Results showed a significant chronological age effect on total distance, Zones 2,3,4,5, attempted high-speed runs and sprints, and top speed for U20 compared to U17 (p < 0.001). Zone 1 was significantly lower in U20 compared with U17 (p < 0.001). There were no significant RAEs within both categories based on running performance (p > 0.05). In conclusion, match running performance increases with age from the U17 to the U20 categories, whereas differences between birth quartiles are negligible. At these ages, the effects of RAE on performance appear to be eliminated, although its influence on selection and participation still remains. Therefore, coaches and practitioners should be aware of this distinction when making decisions related to talent identification and development.