Discrepancies in Sprint and High-Speed Running Loads between Training and Match Play in U17 and U19 Soccer Players

The purpose of the study was to compare training-to-match load ratios between U17 and U19 soccer players, focusing on effective training time, external load, and intensity. Two youth academy teams were assessed: U19 (n = 22; 6 weeks; 59 training weeks) and U17 (n = 21; 11 weeks; 112 training weeks). The external load was tracked using a 10-Hz GPS and included total distance (TD), high-speed running (HSR), sprint distance (SPRm), sprint entries (SPRn), accelerations, decelerations, and impacts (>5 g). Total and effective training time were recorded separately to calculate relative intensities. Generalized linear mixed model was used to compare U17, U19, and U19 excluding one session (U19 MD-2) to ensure equivalent weekly structure. U17 players showed significantly higher training efficiency (ET%: 71.0 ± 7.3%) than U19 players (68.5 ± 4.0%). U19 players demonstrated higher training-to-match load ratios, particularly in HSR (U19: 1.5 ± 0.4; U19 MD-2: 1.2 ± 0.4; U17: 1.0 ± 0.4; p < 0.01) and SPRm (U19: 2.0 ± 1.0; U19 MD-2: 1.8 ± 0.9; U17: 1.0 ± 0.8; p < 0.01). U17 players struggled to replicate match intensities in sprinting and high-speed running. Differences were also observed in acceleration and deceleration profiles. Effect sizes ranged from moderate to large across sprint and HSR metrics. Training-to-match load ratios varied substantially between U17 and U19 players. While U19 players exceeded match intensities in most metrics, U17 players fell short, especially of sprinting demands. These findings support the use of structured high-intensity training and individualized load management to optimize development and prepare youth players for professional demands.