Carb Rinsing: Does It Improve Athletic Performance on Keto?
carb rinsing

Carb Rinsing – What Is It and Does It Work with Keto?

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If you’re spending time on health and fitness websites and blogs, you might have already heard of the term “carb rinsing”, which is a newly-discovered strategy for enhancing performance, used by regular gym-goers and top athletes alike.

Is it compatible with keto diet, though? And what is it exactly?

Let’s find out.

What Is Carb Rinsing?

Carb rinsing or carbohydrate mouth rinse is the practice of taking a gulp of a carb drink (can be a sports drink, for example), swishing it in your mouth and spitting it out without swallowing.

Essentially, you’re rinsing your mouth with carbs dissolved in liquid, hence the name “carb rinsing”. This tricks your body into thinking that you have actually ingested carbs and can boost physical performance.

It does sound pretty weird, so you have every reason to be skeptical. However, it turns out that it’s not just another myth, and that there’s a scientific explanation behind it.

How Does Carb Rinsing Work and What is the Science Behind It

As peculiar as it sounds, carb rinsing could actually have its place in a heavy workout. It does not necessarily influence the perception of fatigue or pleasure, however it does have a noticeable effect on performance and physical output, according to a study from 2017 (1).

Another study points out that the effect is more pronounced when the subjects are in a carb-depleted state (which you are, when doing keto) (2).

Although it’s not yet completely clear why carb rinsing works, it is suggested that it influences neural pathways via the taste receptors in the mouth in a way that improves physical output (3, 4)

It’s important to note that this can be achieved even with carb drinks that aren’t sweet. A solution with maltodextrin, which is tasteless, has a similar effect to a glucose solution (5).

Additionally, ingesting carbs during exercise (a well-known strategy that isn’t really suitable for keto) can result in gastrointestinal discomfort (6).

Carb rinsing does not have a similar effect, due to the fact that the carb drink is not actually ingested.

Should You Try Carb Rinsing On Keto?

To give you a quick answer, maybe.

So far we haven’t found any studies on carb rinsing and people who are doing keto long term, so the evidence is only anecdotal.

Many of the studies cited above concluded that carb rinsing is more effective when done in a fasted state, though, as glycogen stores are at their lowest then. This makes it compatible with keto, as your glycogen stores will be nearly depleted when you’re in ketosis.

Keep in mind that carb rinsing is rather advanced athletic strategy, and might not really be necessary if you are just starting out with exercise.

It’s a tweak to give you a performance boost that will be noticeable if you’re already highly active; otherwise, just sticking to a good exercise routine and letting your body progressively adapt to it is the best thing you can do.

If you’re already very active but are just starting out with keto, in the beginning you might notice a drop in performance – this is a normal part of the fat adaptation process and will improve with time.

To help your body deal with it, make sure you’re supplying it with adequate electrolytes.

Carb rinsing might be beneficial, however it won’t override the side effects of fat adaptation – the best you can do is just to be patient and give your body enough time to deal with the changes in your diet.

If you’re well into keto (and into working out), you can try carb rinsing and see whether it helps you in your workouts – you’re not actually swallowing any carbs, so it shouldn’t have an impact on ketosis.


Nevertheless, as a precaution, you should rinse your mouth with water after carb rinsing. Don’t swallow your saliva, as there might be trace amounts of carbs in it.

You can try out a few different strategies, to see what works best for you.

For example, try carb rinsing in a fasted state when doing intermittent fasting or in a fed state (according to studies, it’s more effective in a fasted state, but these studies weren’t done on people who were following a keto diet), try it in the beginning of your workout, or once you’re already exhausted, and so on.

With some experimenting you’ll find your sweet spot and see what works best for you.

Possible Side Effects of Carb Rinsing

1. You might accidentally swallow the carb solution

The idea is to spit out whatever drink you’re using for carb rinsing, however during a heavy workout you might actually swallow it by mistake. One gulp won’t do anything serious, but try to avoid it.

2. It might trigger carb cravings

Some people are particularly sensitive to anything that tastes sweet and it can trigger an episode of carb cravings for them. If this is your case, proceed with caution.

3. It might have an effect on dental health

If you’re rinsing your mouth with a sugary drink, the health of your teeth might be affected. Rinsing with water afterwards should diminish the negative impact.

What Are Some Other Things You Can Do to Boost Your Performance While Doing Keto?

  • Coffee & Other Forms of Caffeine

Caffeine is one of the most well-known and well-researched stimulants in human history.

If you drink coffee or a strong tea (black, oolong or green) before your workout, it will improve your physical performance and allow you to be faster and have better endurance.

Its effect is mild, especially if you’re used to coffee, but it’s definitely present, and it also acts as an appetite suppressant.

If you are sensitive to caffeine and have problems with your sleep, limit your consumption to the morning hours only.

You can also take caffeine in pill form.

  • MCT Oil / Powder

MCT (short for medium chain triglycerides) is a powerful way to get a boost before a workout.

It is quickly metabolized by the liver to be used as energy straight away, and it increases ketone production.

You can use MCT oil and powders. Some people report stomach issues at higher doses, so when trying it for the first time, start with a small amount.

  • Electrolytes

If you’re not replenishing your electrolytes adequately, your performance will take a hit. This is especially important in the hot summer months, and also if you’re very active.

They will not boost your performance as such, but without them, you’ll certainly feel weaker, so don’t ignore electrolyte supplementation on keto.

  • Pre-workouts

There are thousands of pre-workouts on the market, and you need to carefully check the ingredients to make sure you’re getting your money’s worth.

Many will have caffeine as a main ingredient, so don’t waste your money if the other ingredients don’t have a proven effect.

This might require some research in order to compare different pre-workouts; alternatively, you can make your own pre-workout by mixing MCT oil with coffee.

Whenever buying a pre-workout, check the label for their carb content per dose.

Related: Top 3 Pre Workout Supplements for Low Carb Ketogenic Diet

Our Conclusion

Carb rinsing looks promising, and although it’s not yet completely clear why it is effective, if you’re highly active and looking for a boost in your performance, there’s nothing wrong with trying it out.

It shouldn’t have an effect on your diet, as you’re not actually ingesting the carb drink, however you should be cautious with the possible side effects, such as accidentally swallowing, or triggering carb cravings.

Have you tried carb rinsing already? How do you feel about it? Share your story with us!

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