This randomized, double-blind, four-period crossover trial investigates the acute effects of creatine monohydrate, L-arginine, and their combined administration on anaerobic performance, jump performance, and cognitive reaction time in recreationally active adult males. Eighteen healthy male participants complete four experimental conditions in randomized order: placebo, creatine, L-arginine, and creatine plus L-arginine, with at least 72 hours between sessions. Sixty minutes after supplementation, participants perform the Stroop Color-Word Test, countermovement jump test, and Running-Based Anaerobic Sprint Test. Primary outcomes include peak power, average power, countermovement jump height, and incongruent Stroop reaction time. The study aims to determine whether acute co-supplementation produces greater ergogenic and cognitive benefits than either supplement alone or placebo.