High-carb mouthwash: improved performance by deceiving the brain
It’s been known for some time now that carbohydrates should be consumed during prolonged exercise (exceeding 60 minutes) to achieve high-intensity performance. It was assumed that this would have no effect for shorter intensive exercise (under 60 minutes) because the energy supplies in the body were sufficient. However, in recent years, it’s become clear that carbohydrates can improve performance during shorter intensive exercise. But, only to a limited extent. And not by supplying fuel, but by ‘deceiving’ the brain.
Many studies show that intensive exercise under 60 minutes can be significantly improved by rinsing the mouth with a high-carb drink. You should rinse for five to ten seconds. It seems there is no difference between a sweet or tasteless drink as long as it is a sugar-rich, for example, an isotonic sports drink. Note that so-called zero-calorie drinks have no effect. It makes no difference whether you spit out the sugar-rich drink or actually drink it down after rinsing. In all cases, performance during exercise was demonstrably better compared to rinsing with a sugarless drink.
Moreover, it was recently shown that rinsing the mouth does not necessarily just improve endurance. Long periods of exercise usually result in a gradual slowing of analytical capacity and in longer response times. A recent study shows that rinsing the mouth with a sugar-rich drink can combat the slowing of mental capacity and response times. For intensive exercise lasting about an hour, rinsing your mouth for only five seconds is enough to ensure that your response time does not slow down during exercise.
How is this possible?
Eating a tasty snack immediately makes you feel better when you are hungry. This is remarkable because the nutrients in the snack have not yet been absorbed by the body. So, the mouth must be sending a signal directly to the brain. Rinsing the mouth also activates this connection between mouth and brain. When rinsing your mouth, sugar receptors in the mouth send a signal to the areas of the brain responsible for the perception of pleasant feelings, such as reward and pleasure. The brain translates this signal into the message indicating that calorie-rich nutrients are on the way, which results in the suppression of the feeling of fatigue and a reduced creation of stress hormones. Eventually, the exercise becomes easier and quicker.
In brief, rinsing the mouth for five to ten seconds with a high-carb drink makes exercise under 60 minutes easier and quicker. And, it is not necessary for the body to actually digest the nutrients. The mouth and brain do all the work!
- De Ataide e Silva T, Di Cavalcanti Alves de Souza ME, de Amorim JF, Stathis CG, Leandro CG, Lima-Silva AE. Can carbohydrate mouth rinse improve performance during exercise? A systematic review. Nutrients, vol 6(1) p 1-10, 2013.
- Konishi K, Kimura T, Yuhaku A, Kurihara T, Fujimoto M, Hamaoka T, Sanada K. Mouth rinsing with a carbohydrate solution attenuates exercise-induced decline in executive function. Journal of the International Society of Sports Nutrition, 2017.