Rinsing the mouth with a 6-8% carbohydrate solution (without swallowing) may slightly boost performance during short-duration high-intensity exercise via sensory signals sent to the brain, but this method remains a very specific tool that is of little use to the majority of amateur athletes compared to proper nutrition.

noli's read

The concept of carbohydrate mouth rinsing is based on real physiological foundations. A landmark meta-analysis published in Sports Medicine (2022) confirms that a maltodextrin solution provides a very slight but measurable performance benefit for efforts lasting 30 to 75 minutes. This central mechanism is supported by a randomized controlled trial (RCT) by Chambers et al. (2009), showing through imaging that oral receptors directly activate brain areas associated with reward and motor control. Nevertheless, the idea of a spectacular 3 to 7% gain for everyone is exaggerated. Another 2023 meta-analysis shows that this effect is virtually nonexistent if the athlete has already eaten (fed state), limiting its practical value to elite or fasted athletes. For sessions lasting over 90 minutes, the consensus in sports nutrition is that carbohydrates must be actually ingested to provide fuel for the muscles. Finally, Abbey Sharp's opinion regarding the risk of promoting restrictive behaviors by encouraging spitting out food is a very pertinent warning for maintaining a healthy relationship with food.

the sources

No named source held this one up — that absence is part of the verdict.