Background: While carbohydrate ingestion enhances performance, carbohydrate mouth rinsing (CMR) may confer ergogenic benefits via non-metabolic pathways; however, findings remain mixed.

Aim: To examine the acute effects of a 6.4% glucose mouth rinse on anaerobic performance and fatigue in adolescent wrestlers.

Martials and Methods: In a randomized, single-blind crossover design, sixteen trained male wrestlers (16.75 ± 1.4 y; 64.94 ± 8.4 kg; 1.66 ± 0.07 m) completed two trials (CHO and placebo) separated by a 1-week washout. Anaerobic performance (peak, average, and minimum power) and fatigue index were assessed with the Running-based Anaerobic Sprint Test (RAST). During the 10-s recovery of sprints 1, 3, and 5, participants completed 5 s active rest followed by 5 s mouth rinse (25 mL of 6.4% glucose or water).

Results: CHO mouth rinse produced significant improvements in average power (p = 0.001, d = −2.38), peak power (p = 0.03, d = −0.92), and minimum power (p = 0.002, d = −1.74), while no significant change was observed in fatigue index (p = 0.39, d = 0.32).

Conclusion: CMR boosts anaerobic power but not fatigue resistance, supporting its potential as a practical ergogenic aid for high-intensity, intermittent sports.