Interdependent Development of Physical and Cognitive Skills in U12 Soccer Players: Sprinting, Agility, and Decision-Making Are Interconnected

Background: Change of direction (COD) and sprint abilities are essential in soccer, while reactive agility involves decision-making and perceptual/cognitive skills. This study aimed to examine the relationships between sprint speed, COD, and reactive agility in U12 soccer players. Methods: Thirty-three male players (age 10.40 ± 0.32 years) completed sprint tests (5 m, 10 m, 15 m), the Modified Agility T-Test (MAT), and the Y-Shaped Reactive Agility (Y-RSA) test, across two sessions. Results: The sprint, COD, and reactive agility tests showed high reliability. The Y-RSA test demonstrated strong reliability in regard to the initial sprint, COD-phase time, and total time. Significant correlations were found between sprint, COD, and reactive agility metrics. The sprint times were positively associated with the MAT and reactive agility times (e.g., sprint 15 m vs. total Y-RSA time: r = 0.740, p < 0.01). The smallest worthwhile changes (SWCs) indicated that these tests effectively detect performance improvements. Conclusions: This study demonstrated significant correlations between sprint speed, change of direction, and reactive agility in U12 soccer players, with the 15 m sprint showing the strongest association with reactive agility. These findings support the combined use of physical and perceptual/cognitive assessments to better inform soccer-specific training and evaluate the performance of youth players.