Effects of training repetition on young footballers’ tactical and physical performances: free and conditioned large-sided games

This study evaluated the consequences of repeating the same large-sided games, playing free or conditioned, during several training sessions on young footballers’ tactical and conditional performances and their variabilities. Thirty-two U14 and U16 developmental male footballers participated in the study. Both teams, divided into two balanced groups (free play and conditioned), faced each other during three eight-a-side games (seven vs seven, plus goalkeepers) during three training sessions. The free-play groups played as they pleased, while the conditioned groups played the games conditioned by tactical instructions. Tactical performance was assessed by central tendency and normalized approximate entropy measures of the distance of each player to the team centroid (m) and the distance of each player to their mean position (m), while the conditional performance was assessed by total distance (m) and walking, jogging, running, and sprinting distances traveled (m), and number of accelerations and decelerations performed. Whereas players’ average tactical and conditional responses scarcely varied between sessions, inter- and intra-player variabilities were always considerable (coefficient of variation >10%) regardless of the task conditions and the age group. In addition, all footballers’ conditional variability was substantially higher at faster speeds (jogging, running, and sprinting distances) than at slower ones (total distance and walking distance traveled), and for accelerations and decelerations performed. Implementing large-sided games with or without tactical instructions may be an appropriate training strategy to ensure stable and constant average responses for the team. Nevertheless, academy football coaches should bear in mind and manage the variability between and within players.