Football-Specific Performance and Cognitive Fatigue Resistance Following Supplementation with Two Phosphatidylserine Doses Combined with Taurine and Caffeine in Professional Male Football Players: A Randomized, Triple-Masked, Placebo-Controlled Trial

Background/Objectives: Cognitive fatigue and impaired psychomotor function may contribute to reductions in football-specific performance during prolonged match-like activity. This study evaluated cognitive, psychomotor, sprint, and football-specific locomotor responses to multi-ingredient protocols containing taurine, caffeine, and either 300 or 600 mg·day−1 of phosphatidylserine in professional male football players. Methods: In this randomized, triple-masked, placebo-controlled, parallel-group trial, 97 professional male football players were allocated to placebo (PLA, n = 24), taurine plus caffeine (TC, n = 24), taurine plus caffeine plus phosphatidylserine 300 mg·day−1 (TCP-300, n = 24), or taurine plus caffeine plus phosphatidylserine 600 mg·day−1 (TCP-600, n = 25) for 14 days. Taurine and caffeine doses were 1500 mg·day−1 and 200 mg·day−1, respectively. Outcomes included 30 m sprint performance, visual and auditory reaction time, Stroop-task performance, perceived mental fatigue, GPS-derived locomotor variables, and post-intervention first-to-second-half performance-loss indices during a standardized football-specific exercise protocol. Results: The baseline-adjusted ANCOVA demonstrated a significant treatment-group effect on post-intervention 30 m sprint time. After Holm–Bonferroni correction, significant treatment-related effects remained for Stroop reaction time, visual reaction time, and perceived mental fatigue. No statistically significant treatment-related effect was observed for auditory reaction time (unadjusted p = 0.074; Holm-adjusted p = 0.096). During the post-intervention standardized football-specific protocol, baseline-adjusted GPS-derived locomotor outcomes differed significantly between groups. First-to-second-half performance-loss indices also differed between groups, with the smallest post-intervention losses generally observed in TCP-600. Because comparable decline indices were unavailable at baseline, these findings do not represent intervention-related changes in fatigue resistance. Conclusions: Under the present 14-day experimental conditions, the multi-ingredient protocols containing taurine, caffeine, and phosphatidylserine were associated with more favorable selected cognitive and psychomotor outcomes, 30 m sprint performance, and baseline-adjusted GPS-derived locomotor outcomes than placebo. The groups also differed in post-intervention first-to-second-half performance loss during the standardized football-specific protocol. Because corresponding decline indices were not assessed at baseline, these findings do not demonstrate an intervention-related improvement in fatigue resistance. Numerically more favorable values were observed for several outcomes in TCP-600; however, differences between TCP-300 and TCP-600 were modest and not consistently statistically significant, and the study was not specifically powered to establish a dose–response relationship. Because phosphatidylserine was not tested independently, these findings should be interpreted as responses to the combined multi-ingredient supplementation protocols rather than as effects of phosphatidylserine alone.