Effects of Carbohydrate and Caffeine Mouth Rinsing Methods on Repetitive Kick Force and Duration, and Hand Reaction Time in Karate Athletes

The effect of carbohydrate (CHO) and caffeine (CAF) solutions rinsing in the mouth in combat sports where high-intensity movements are performed intermittently despite fatigue is unknown. This research was carried out to investigate the effects of rinsing CHO and CAF solutions in the mouth on kick force, duration, and hand reaction time in karate athletes. 16 male trained karate players (average age 21.6 years, weekly training time 8.4 hours, training experience 7.8 years) voluntarily participated in the study. In a replicated, double-blind, placebo-controlled, and crossover design study, after the 10 seconds mouth rinsing of CHO (6.4% maltodextrin), CAF (1.2%), and placebo (water) solutions in sessions, repeated sprint test (6sec sprint ×10 repetitions, with 30sec rest) on a bicycle ergometer, after light stimuli kick test (consecutive 5 times), hand reaction time test (consecutive 5 times), kick test (consecutive 5 times), hand reaction time test (consecutive 5 times) were performed respectively. The results obtained from the tests in the constructed protocol by causing fatigue (peak power, average power, minimum power, power drop; kicking reaction time, strength, power, and time; hand reaction time) were compared between sessions. The highest peak power and average power outputs (W/kg) obtained from the repeated sprint test were obtained in the CAF session, and the best kick and hand reaction times (ms) were obtained in the CAF session in the 2nd set of tests. The results obtained from this study suggest that the CAF mouth rinsing method can improve kick and hand reaction time despite fatigue in karate competitions.