Combined effects of age, pitch size, playing position and tactical formation on training load in youth soccer players during small sided games

This study aimed to explore the combined effects of age, pitch size, playing position and tactical formation (TF) on locomotor and physiological load in youth soccer players during small-sided games (SSGs). A total of 32 sub-elite soccer players (U19 = 14; U16 = 18) engaged in various 7-a-side SSGs with distinct spatial dimensions (232 m 2 vs 132 m 2 per player), TF (1-2-3-1 vs 1-3-1-2) and specific playing positions (CD = central defender; M = midfielder; W = winger; FW = forward). Relative (m·min −1 ) total distance (TD), high intensity running distance (HIRD), accelerations, decelerations, maximum speed (Speed MAX ), average speed (Speed AVG ), high metabolic load distance (HMLD) and relative heart rate (%HR MAX ) were collected using WIMU PRO™ GPS devices (Hudl, USA). Generalized linear mixed models revealed that U19 players exhibited higher values of TD, Speed MAX and Speed AVG than U16 players (p < 0.05). SSGs conducted in larger pitch size registered higher values of TD, HIRD, HMLD, Speed MAX , and Speed AVG than SSGs with smaller pitch size (p < 0.05). Regarding playing position, M, W and FW had more TD, HIRD and Speed AVG than CD, while W and FW showed higher values of HMLD, accelerations and decelerations distance than CD (p < 0.05). M exhibited the highest relative HR MAX in comparison to other playing positions (p < 0.05). Notably, no effects on locomotor and physiological load emerged concerning different TFs. In conclusion, soccer coaches should consider the effect of the age, pitch size and playing position on the training load when designing SSGs in youth players.