Effects of a short-term in-season break on repeated-sprint ability, jump height and locomotor performance in small-sided games in female soccer players

The current study aimed to analyse the effects of an in-season break period (2-week) on specific performance in amateur young female soccer players. Twelve female soccer players completed four assessment sessions, two before (BD-d1 and BD-d2) and two after (AD-d1 and AD-d2) a 2-week in-season break detraining period (both separated by 24 h). In each session, players completed a repeated sprint ability test (repeated sprint ability = 8 sprints of 30 m with 25 s of recovery), a countermovement jump test and locomotor performance in small-sided games (small-sided games = 3 sets of 5 min in a 5 vs. 5). Players exhibited a significant decrease in mean of repeated sprint ability (mean time of 8 sprints, p = 0.000, effect size = 2.04) and countermovement jump (p = 0.009, effect size = 1.39) performance between BD-d1 and AD-d1. The percentage of change between BD-d1 and BD-d2 from AD-d1 and AD-d2 shows significant differences (p = 0.05, effect size = 1.12) in best of repeated sprint ability (best time of 8 sprints) but not (p = 0.517, effect size = 0.31) in mean of repeated sprint ability. Significantly less high-intensity acceleration was performed in BD-d2 and AD-d2 from BD-d1 (p = 0.003, effect size = 3.21 and p = 0.002, effect size = 3.25, respectively). Only a 2-week in-season break inactivity was sufficient to decrease mean of repeated sprint ability and countermovement jump performance but not the best of repeated sprint ability. Therefore, it is necessary to apply specific training strategies to prevent decreases in performance in female soccer players in specific periods of the season.