Deceleration specific isometric exercises acutely enhance change of direction performance in male youth academy soccer players

Post-activation performance enhancement (PAPE) is a neuromuscular mechanism that can acutely enhance explosive movements such as change of directions (COD). The effectiveness of different deceleration specific isometric positions to elicit a PAPE effect on COD performance has not been previously investigated. Therefore, the aim of this study was to investigate the acute effects of two deceleration specific isometric exercises associated with the early (DEC_EISO) and late (DEC_LISO) deceleration subphases on COD performance. Sixteen male youth academy soccer players competing in the U16–U17 age categories completed both deceleration specific isometric protocols in a counterbalanced repeated-measures design. Performance was measured using the traditional 5-0-5 COD test at four intervals (0, 4, 8, and 12 minutes post-activation) for both right and left leg turns. Data were analysed using repeated measures ANOVA, with Bonferroni-adjusted post hoc tests. Parametric paired t-tests was used to compare differences in improvements between DEC_EISO and DEC_LISO. Significant improvements in COD performance were observed following both deceleration specific isometric protocols, with the most pronounced gains occurring at the 8th minute. At the 8th minute, performance was significantly better following the DEC_EISO compared to the DEC_LISO (p = 0.002), with a large effect size (g = 0.90). These findings suggest that deceleration specific isometric exercise can have a significant impact on enhancing short-term COD performance. The DEC_EISO position produced superior results, particularly in the 8th minute postactivation, highlighting its potential usefulness in pre-training or competition warm-ups for COD-based sports like soccer.