Carbohydrate mouth rinse and performance in cyclists: effects of different types of carbohydrates and the placebo effect induced by mouth rinse

This study investigated whether carbohydrate (CHO) mouth rinsing with maltodextrin or fructose improves time-trial performance in male amateur cyclists and whether mouth rinsing induces a placebo effect. Twelve male amateur cyclists participated in a randomized, double-blind, placebo-controlled crossover study and performed a cycling protocol under four conditions: mouth rinsing with maltodextrin, fructose, or placebo, and a no-rinse control condition. The protocol involved 15 minutes of cycling at 65% of Wmax at 90 rpm, followed by a 15-minute time trial in which participants were instructed to produce as much work as possible. Performance was assessed by measuring power output. Power output did not differ among conditions during the time trial (maltodextrin: 247.0 ± 42.0 W; fructose: 242.8 ± 38.1 W; placebo: 246.8 ± 38.8 W; control: 243.2 ± 38.9 W; p = 0.989). In conclusion, CHO mouth rinsing with maltodextrin or fructose did not improve 15-min cycling time-trial performance, and the act of rinsing did not induce a placebo effect.