Spanish Elite Soccer Reserve Team Configuration and the Impact of Physical Fitness Performance.

The aim of this study was threefold: 1) to assess the configuration of an elite reserve soccer team, 2) to compare physical fitness performance of promoted and new players according to the playing position, and 3) to analyze the level of competitive participation attained by these players. We considered physical fitness tests (5 m and 15 m sprint, countermovement jump [CMJ] and aerobic endurance) performed by 192 players (age = 20.2 ± 2.3 years) enrolled in the reserve team of a Spanish La Liga club from 1994 to 2013. The players were classified according to the previous club criterion (promoted from the soccer academy and new players signed from other clubs), b) their playing position, and c) the competitive level attained until the 2016/2017 season (Spanish 1st and 2nd Divisions and the remaining competition levels). The proportion of promoted and new players was similar (p = 0.47). Overall, no substantial differences (unclear-small) were found in physical fitness performance between promoted and new players. Considering the playing position, promoted lateral defenders (LDs) showed better sprinting (ES = moderate) and CMJ (ES = moderate) performance than new LDs. In addition, promoted central midfielders (CMs) demonstrated better performance in the 5 m sprint and the CMJ (ES = moderate) than new CMs. The percentage of players who later competed in the Spanish 1st and 2nd Divisions was greater in promoted players compared to new players (p = 0.006). Physical fitness performance did not determine the selection of new players in a soccer elite reserve team. We may conclude that soccer academies should prioritize the selection and the training process of youth soccer players.