What Is Carbohydrate Mouth Rinsing?

Alfredo Valdés 7 min. of reading Sport Performance Leave a comment

Instead of drinking the carbohydrate-rich beverage, you rinse your mouth with it and spit it out. It has been scientifically shown that it can improve your sports performance.

How do you do a carbohydrate mouth rinse?

Add 50g of dextrose to half a litre of water.
Rinse your mouth for 5-10 seconds with a sip of the solution and spit it out.
Repeat every 5-10 minutes.
You can follow this protocol for 60-75 minutes of exercise.

What you should keep in mind:

It is more effective if you train fasted or with low energy availability.
It is intended for high-intensity, intermittent efforts lasting between 30 and 75 minutes.
If your training session lasts longer than 90 minutes, you need to consume the carbohydrate drink: mouth rinsing is no longer enough.

What can you expect?

An average performance improvement of 2-3%, with studies reporting a range from 0% to 12% depending on the context. It is a protocol supported by Jeukendrup (2014) and the ACSM (2016) for short, high-intensity training sessions. :contentReference[oaicite:0]{index=0}

Which sports does it work best for?

Carbohydrate mouth rinsing is not a universal strategy. It works particularly well for:

Cycling and running in high-intensity events lasting around one hour.
“Train low, compete high” training protocols.
Fasted sessions or training with low glycogen stores.

Quick summary: carbohydrate mouth rinsing involves rinsing your mouth with a carbohydrate solution and spitting it out without swallowing. It activates sweet taste receptors that “signal” the brain and delay the sensation of fatigue. It works mainly during 30-75 minutes of high-intensity exercise, especially when training fasted.

How does it help the brain “not notice” fatigue?

The exact mechanism is still complex, but there is a clear clue: activation of the “sweet taste receptors” (T1R2 and T1R3) in your mouth sends signals to certain areas of the brain, increases the flow of oxygen-rich blood and helps maintain neurotransmitter balance.

The most widely accepted hypothesis points to the so-called “central governor” proposed by Hill: carbohydrate mouth rinsing would block brain activity that limits the recruitment of motor units.

Put simply: we “trick” certain regions of the brain so that they do not perceive the situation as fatiguing and do not limit muscular performance prematurely.

What does the scientific evidence say?

It may sound almost like a bar trick, but the evidence supports it: this technique improves performance during short, high-intensity efforts to a similar extent as drinking the solution, with the added advantage of not having to ingest anything during the event.

So much so that it is now the reference model proposed by Jeukendrup (2014) for sports lasting 30 to 75 minutes. The mechanisms explaining this effect are still largely hypothetical: we understand the basis, but not every detail.

The International Society of Sports Nutrition (2018) classifies carbohydrates as a category “1” evidence supplement: strong evidence of effectiveness and a favourable safety profile for improving sports performance.

In the studies reviewed by de Ataide et al. (2019), carbohydrate mouth rinsing improved performance in high-intensity tests by an average of 2.8%.

The American College of Sports Medicine (ACSM), in its 2016 position stand, recognises carbohydrate mouth rinsing as an interesting strategy for efforts lasting 45-75 minutes.

Why are carbohydrates still key to performance?

We have known for decades that consuming carbohydrates during prolonged aerobic exercise (around 2 hours) consistently improves performance, regardless of the sport, duration or intensity.

“For high-intensity performance, carbohydrates are still king,” summarises Kanter (2018).

One of the landmark studies is that of Jeukendrup (1997), the researcher who has studied this area most extensively:

He found that a carbohydrate-electrolyte drink improved performance by 2.3% in short, high-intensity tests (lasting approximately one hour), reducing the time required to complete the target and increasing maximum power output.

The reason? Something as simple as energy availability.

Thanks to highly branched carbohydrate sources with weak glycosidic bonds and high molecular weight — such as amylopectin, maltodextrin, HBCD or dextrose — the body can efficiently absorb monosaccharides even during exercise, when intestinal blood flow is drastically reduced.

Frequently asked questions about carbohydrate mouth rinsing

Does carbohydrate mouth rinsing replace drinking a sports drink?
Not always. If your training session lasts longer than 90 minutes, you need to actually consume carbohydrates: mouth rinsing is no longer sufficient beyond this point.
Will any sugary drink work?
It is preferable to use the carbohydrate sources that have been studied most extensively for this protocol: dextrose and maltodextrin.
Who is less likely to benefit from it?
If you already follow a high-carbohydrate diet, you may notice less of a difference with this protocol. It also makes little sense to combine it with an intra-workout drink that already contains carbohydrates.
Does it work the same way for strength training?
No. In strength training, carbohydrate mouth rinsing has not been shown to improve 1RM or the number of repetitions performed (Dunkin, 2017; Clarke, 2015; Painelli, 2011).
How long does the effect last?
The benefit has mainly been documented during the exercise itself, within the 30-75-minute window in which the protocol is applied, rather than as a subsequent cumulative effect.

Bibliographic Sources

Ataide-Silva, T., Ghiarone, T., Bertuzzi, R., Stathis, C. G., Leandro, C. G., & Lima-Silva, A. E. (2016). CHO Mouth Rinse Ameliorates Neuromuscular Response with Lower Endogenous CHO Stores. Medicine and Science in Sports and Exercise, 48(9), 1810–1820.
Chandrashekar, J., Hoon, M. A., Ryba, N. J. P., & Zuker, C. S. (2006). The receptors and cells for mammalian taste. Nature, 444(7117), 288–294.
de Ataide e Silva, T., Di Cavalcanti Alves de Souza, M. E., de Amorim, J. F., Stathis, C. G., Leandro, C. G., & Lima-Silva, A. E. (2013). Can carbohydrate mouth rinse improve performance during exercise? A systematic review. Nutrients, 6(1), 1–10.
Jeukendrup, A. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Medicine (Auckland, N.Z.), 44 Suppl 1(Suppl 1), S25-33.
Jeukendrup, A., Brouns, F., Wagenmakers, A. J., & Saris, W. H. (1997). Carbohydrate-electrolyte feedings improve 1 h time trial cycling performance. International Journal of Sports Medicine, 18(2), 125–129.
Kanter, M. (2018). High-Quality Carbohydrates and Physical Performance: Expert Panel Report. Nutrition Today, 53(1), 35–39.
Kerksick, C. M., Wilborn, C. D., Roberts, M. D., Smith-Ryan, A., Kleiner, S. M., Jäger, R., … Kreider, R. B. (2018). ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition, 15(1), 38.
Noakes, T. D. (2000). Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance. Scandinavian Journal of Medicine & Science in Sports, 10(3), 123–145.
Ren, X., Zhou, L., Terwilliger, R., Newton, S. S., & de Araujo, I. E. (2009). Sweet taste signaling functions as a hypothalamic glucose sensor. Frontiers in Integrative Neuroscience, 3, 12.
Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise, 48(3), 543–568.
Vitale, K., & Getzin, A. (2019). Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients, 11(6).

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