Congested Period in Professional Youth Soccer Players Showed a Different High Decelerations Profile in the Group Performance and a Specific Positional Behaviour

Present soccer demands are increasing in terms of running requirements and the number of matches until youth soccer players experience several periods of fixture congestion during the season. Currently, congested periods have not been extensively studied in this population. For this reason, this study aimed to compare the running demands of professional youth soccer players in congested periods according to their specific playing positions. Twenty youth players were grouped according to their position: Central Defenders (CD), Fullbacks (FB), Midfielders (MF), Wide Midfielders (WM) and Strikers (ST). A GPS system was used to monitor the players during the first (M1), second (M2) and third (M3) matches played during a congested period, measuring their total distance covered (TDC), DC 18.0–20.9 km·h(−1), DC 21.0–23.9 km·h(−1), DC > 24.0 km·h(−1), number of high accelerations (>2.5 m·s(−2)), number of high decelerations (<2.5 m·s(−2)) and peak speed (km·h(−1)). M1, M2 and M3 showed the same TDC, DC 18.0–20.9 km·h(−1), DC 21.0–23.9 km·h(−1), DC > 24.0 km·h(−1), number of high accelerations, and peak speed (p > 0.05). The statistical analysis showed significant differences between M1, M2 and M3 in the decelerations recorded between M1 and M3 (p < 0.05). Likewise, each position showed specific behaviours during the congested period, with all showing at least one difference in DC 18.0–20.9 km·h(−1), 21.0–23.9 km·h(−1) or >24.0 km·h(−1) between M1, M2 and M3 (p < 0.05). In conclusion, coaches should pay attention to the fatigue produced by the number of high decelerations. Secondly, an individualized training protocol should be considered according to the running requirements of each position when youth professional soccer players are involved in a congested period.