(1) Background: Carbohydrate mouth rinsing (CMR) stimulates the central nervous system and improves motor control. However, no studies have examined the effects of CMR on softball batting performance. The purpose of this study was to investigate the effect of CMR on softball batting performance. (2) Methods: Fifteen trained female collegiate softball players (age: 20.6 ± 0.9 years; height: 159.5 ± 5.2 cm; body weight: 58.1 ± 6.9 kg) completed two trials in a randomization crossover trail, in which they rinsed their mouths for 20 s with 25 mL of either 6.4% maltodextrin (CMR) or a placebo (PLA). After rinsing, the Posner cueing task and grip force, counter-movement jump (CMJ) and batting tests were performed in sequence. A tanner tee was utilized to hit five sets of five balls at a time, with a minimum 3 min rest between sets. The batting test recorded the average exit velocity, maximum exit velocity and launch angle consistency. The standardized standard deviation (SD) for launch angle represents the standardized variability. (3) Results: The consistency of the launch angle of the CMR trial was significantly greater (p = 0.025; Cohen's d = 0.69) than that of the PLA trial. There were no significant differences in the Posner cueing task, grip strength, vertical jump, or exit velocity. (4) Conclusions: The findings of this study indicate that CMR enhances the launch angle consistency of all-out-effort batting, but does not influence the exit velocity of softball hitting.
Keywords: ergogenic aids; exit speed; launch angle.