Seasonal analysis of training and match running demands in U15-U16 elite Spanish football players

This study aimed to quantify the running demands of U-15 and U-16 elite soccer players across both training and match-play. Forty-five male youth soccer players (U-15: n = 21, U-16: n = 24) from the same club were monitored using 18 Hz Global Positioning System (GPS) technology during training sessions (U-15: n = 106, U-16: n = 134) and matches (U-15: n = 41, U-16: n = 42) throughout the 2022–2023 season. U-16 players, particularly fullbacks, demonstrated greater running demands across several metrics compared to U-15 players during matches. U-16 wide midfielders recorded higher maximal sprint speeds (p < 0.001, ES: 1.13), along with a greater number of accelerations (p < 0.001, ES: 1.72) and decelerations (p = 0.006, ES: 0.92), relative to the U-15 group. However, U-15 center backs (p = 0.030, ES: −0.75), and central midfielders (p < 0.001, ES: −1.45) performed a significantly higher number of decelerations during matches than their U-16 counterparts. In training, U-16 players exhibited higher maximal sprinting speed, apart from central forwards (p = 0.078, ES: 0.52). Accelerations and decelerations were greater in training than in match-play, unlike other parameters. In conclusion, running demands in youth soccer players are influenced by both playing position and age, with differences observed between U-15 and U-16 players. These findings can inform coaches regarding age-specific training strategies and talent development programs by implementing position-specific drills or tailored load management strategies in youth soccer academies. Understanding these variations assists in optimizing training regimens to improve player performance and progression to higher levels of competition.