Touch Restriction Versus Free-Play Small-Sided Games in Soccer: Acute Effects on Serum BDNF, Executive Function, and...

This study aimed to compare the acute effects of two 4v4 small-sided game (SSG) formats, touch-restricted SSG (SSGt) and free-play SSG (SSGf), on serum brain-derived neurotrophic factor (BDNF) levels, cognitive performance, and technical actions in young male soccer players. Thirty-two young male soccer players completed two 4v4 SSG conditions in a randomized crossover design: SSGt (a maximum of two ball touches per possession) and an SSGf. Serum BDNF was measured before and after each session. Executive function was assessed with the Stroop task, cognitive load was evaluated with the Rating Scale of Mental Effort (RSME), and technical actions were analyzed through match performance metrics. Internal load was monitored using heart rate, rating of perceived exertion, and blood lactate levels. Serum BDNF increased significantly only in the SSGt condition, with higher post-exercise values than in the SSGf condition. Mental effort was also significantly greater in SSGt. Executive function performance improved only in SSGt, as reflected by faster completion time in the incongruent color-word interference condition, whereas errors and corrections did not differ between conditions. Moreover, SSGt showed higher numbers of successful passes and shots, fewer unsuccessful passes, and lost balls, whereas interceptions were higher in SSGf. In conclusion, 4v4 SSG with a touch restriction may be a useful strategy for shaping acute neurotrophic, executive-function, and technical-action responses in soccer players. These findings suggest that touch restrictions may help coaches broaden the training stimulus of SSG by increasing cognitive demands without reducing technical effectiveness. TRIAL REGISTRATION: This study was retrospectively registered at ClinicalTrials.gov (Identifier: NCT07395765).