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Nutrition5 min read

Carbohydrate mouth rinse: does swishing a sports drink work?

In events of about an hour, your muscles rarely run out of fuel, yet carbohydrate drinks still seem to help. The reason appears to be your mouth: receptors there detect carbohydrate and signal the brain, which can make hard effort feel easier.

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A cyclist on an indoor trainer drinking orange sports drink in his garage.

The short answer

A carbohydrate mouth rinse means swilling a sports drink round your mouth for 5–10 seconds and spitting it out. In hard efforts of about 45–75 minutes it can give a small performance boost, mainly when you have not eaten beforehand (Brietzke et al., 2019). It is useful when drinking upsets your stomach.

  • Sports nutrition guidance lists mouth rinsing as an option for 45–75 minute events (Thomas, Erdman and Burke, 2016).

How does a carbohydrate mouth rinse work?

Mouth rinse and exercise performance

Swishing sugar water during a workout: how to do it

  1. Step 1

    Choose the drink

    A normal sports drink of about 6% carbohydrate works. Sweeteners alone do not.

  2. Step 2

    Swill for 5–10 seconds

    Take about 25 ml, swill it round your whole mouth, then spit it out.

  3. Step 3

    Repeat

    Rinse every 10–15 minutes during the hard part of the session or race.

When to rinse and when to swallow

Sports nutrition guidance suggests small amounts of carbohydrate, including mouth rinsing, for 45–75 minute events, and swallowing carbohydrate for longer ones (Thomas, Erdman and Burke, 2016). Find your hourly carbohydrate for longer races.

People also ask

Is it better to swallow or spit?

For events over about 75 minutes, swallow. For shorter hard efforts, either works; rinsing avoids stomach upset.

Does mouth rinsing help weight training?

The evidence is mainly from cycling and running; results in lifting are mixed.

What drink should I use for a mouth rinse?

A sports drink of about 6% carbohydrate, as used in the studies. Diet drinks with sweetener only did not work.

Does it work after breakfast?

The benefit was smaller when athletes had eaten.

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Scientific References & Evidence

  1. Brietzke, C., Franco-Alvarenga, P.E., Coelho-Júnior, H.J., Silveira, R., Asano, R.Y. and Pires, F.O. (2019) 'Effects of carbohydrate mouth rinse on cycling time trial performance: a systematic review and meta-analysis', Sports Medicine, 49(1), pp. 57-66. doi: 10.1007/s40279-018-1029-7. Available at: https://doi.org/10.1007/s40279-018-1029-7
  2. Carter, J.M., Jeukendrup, A.E. and Jones, D.A. (2004) 'The effect of carbohydrate mouth rinse on 1-h cycle time trial performance', Medicine & Science in Sports & Exercise, 36(12), pp. 2107-2111. doi: 10.1249/01.mss.0000147585.65709.6f. Available at: https://doi.org/10.1249/01.mss.0000147585.65709.6f
  3. Chambers, E.S., Bridge, M.W. and Jones, D.A. (2009) 'Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity', The Journal of Physiology, 587(8), pp. 1779-1794. doi: 10.1113/jphysiol.2008.164285. Available at: https://doi.org/10.1113/jphysiol.2008.164285
  4. Thomas, D.T., Erdman, K.A. and Burke, L.M. (2016) 'Nutrition and athletic performance', Medicine & Science in Sports & Exercise, 48(3), pp. 543-568. doi: 10.1249/MSS.0000000000000852. Available at: https://doi.org/10.1249/MSS.0000000000000852

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Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to your doctor or a health professional.