Cognitive Fatigue

This study will examine whether a 28-day supplementation protocol containing taurine, caffeine, and phosphatidylserine can help professional male football players maintain physical performance, cognitive function, recovery-related readiness, and selected football-specific perceptual-cognitive performance. Participants will be randomly assigned to receive either placebo or a phosphatidylserine-containing multi-ingredient supplement. Before and after the supplementation period, players will complete non-invasive assessments such as sprint testing, reaction-time testing, heart rate variability monitoring, wellness/readiness questionnaires, mental-fatigue measures, and selected football-specific perceptual-cognitive tasks where available. The study is designed as an external validation and extension of responder profiles derived from previous randomized controlled trials. Data from previous trials and this validation cohort will be used to examine whether baseline physical, cognitive, autonomic, fatigue-related, recovery-related, or perceptual-cognitive characteristics can predict which players are most likely to benefit from phosphatidylserine-containing multi-ingredient supplementation.