Effects of Carbohydrate Mouth Rinse on Human Capacity and Performance-A Systematic Review and Meta-Analysis of 90 Controlled Trials.

Objective

The aim of the current systematic review and meta-analysis was to examine the acute effects of carbohydrate (CHO) mouth rinse on exercise capacity and performance in humans of any health and fitness status.

Methods

We registered our systematic review with PROSPERO (CRD42018085308). Eligibility criteria included adult humans > 18 years old at any health and fitness status undertaking any CHO mouth rinse prior and during of any type of acute exercise session.

Results

We included 90 crossover design-controlled trials. We found improvements in distance covered (Hedges' g = 0.17; 95% CI 0.03 to 0.30, p = 0.02; τ2 = 0.00; I2 = 0%; Q(14) = 9.61, p > 0.05), performance time (Hedges' g = -0.15; 95% CI -0.25 to -0.05, p < 0.01; τ2 = 0.008; I2 = 9.3%; Q(34) = 76.48, p < 0.01), speed performance (Hedges' g = 0.17; 95% CI 0.05 to 0.30, p < 0.01; τ2 ≈ 0; I2 = 0%; Q(23) = 22.73, p > 0.05), workload (Hedges' g = 0.25; 95% CI 0.08 to 0.41, p < 0.01, τ2 = 0; I2 = 0%; (Q(9) = 7.37, p > 0.05) and maximum voluntary contraction (MVC) (Hedges' g = 0.18, 95% CI 0.02 to 0.34, p = 0.03; τ2 = 0; I2 = 0%; (Q(10) = 7.73, p > 0.05). No effect of CHO mouth rinse on muscular endurance, maximum power output, or maximum oxygen consumption (VO2max) was found (p > 0.05).

Conclusions

The available evidence suggests that CHO mouth rinse can produce a small, outcome-dependent ergogenic effect in distance covered, performance time and speed performance as well as small improvements in workload, with less robust evidence for MVC-evidence that mainly applies to male participants. The practical importance of these findings is likely to vary according to the exercise context and competitive context.