Variations of physical performance and training load between higher- and lower-level young soccer players

Abstract Purpose Systematic monitoring of physical performance and training load is crucial to optimize adaptation and prevent performance decline across the soccer season, particularly among developing players. This study aimed to compare seasonal changes in physical performance and training load (TL) between higher- and lower-level youth soccer players. Methods Fifteen male players (U23-U19) from the same professional academy (lower-level [LL] = 8; higher-level [HL] = 7) were monitored with 10-Hz global positioning system (GPS) units across 23 weeks, divided into the first (12 weeks) and second (11 weeks) periods of the competitive season. Three stages of evaluation were selected (early-season test [T0], mid-season test [T1], and end-season test [T2]). The battery of physical tests included the countermovement jump (CMJ) test, 20-m sprint test (T10, T10–20, and T20), V-Cut test (V-Cut), and 30–15 intermittent fitness test (30-15 IFT [VIFT]). Results Significant group x time interactions were found in very high-intensity running (VHIR) for the TL season ( p = 0.020 and 0.013, respectively) and sprint times at mid-season ( p = 0.029, 0.003, and 0.001). HL accumulated significantly greater TL in all metrics, particularly during the first period, whereas LL players covered less sprinting distance. Reduced high-speed exposure was associated with a decline in intermittent running capacity across the season. Conclusions A higher intensity load accumulated until the mid-season with a horizontal load distribution in the central days of the training week develops the sprint performance and intermittent running capacity in academy soccer players.