Carbohydrate Mouth Rinse, for Dummies

Only rinsing in the mouth?

With carbohydrate drinks?

How does that work?

I know it sounds weird…

But we cyclists are fully aware of our metabolic dependence for carbs on and off the bike. On the bike, we sip in isotonic drinks, gels, energy bars, gummies, bananas and other “natural foods” that are becoming trendy with all the “organic” and “eat-natural-unprocessed-foods-only” maniac-type trends.

Off the bike, we feast on pasta (it can only be pasta right?!) at dinner before a heavy training or race, at breakfast, depending on the part of the planet we are about to pedal. Since the earliest reports on dietary intake in the Tour de France from the 80’s, cyclists have been relying on bread, pastry products, croissants, jams and other miscellaneous foods.

The effect of carbohydrate rich foods on cycling endurance performance is well embedded both in the scientific literature and on cyclists brain wiring. It seems quite acceptable among amateur and professional riders that carbohydrates are the main fuel for long and intense rides. However, many cyclists might be unaware of the effects on cycling performance of simply rinsing in the mouth a carbohydrate rich drink for a few seconds.

What are the advantages of rinsing carbohydrates in the mouth?

Since many cyclists started adopting training low strategies where carbohydrate intakes are periodized in order not only to fuel for different workouts, but to promote training adaptations while providing inferior carbohydrate intakes bellow the recommendations. In such conditions it becomes necessary minimize the negative effects of low carbohydrate intake such as performance impairment at higher intensities which restricts the workout sessions in such conditions to a low intensity workout. There are many variants of training low that might be: training in the fasted state, training with low glycogen stores, training twice a day or training with low or no carbohydrate intake during a cycling session.

Studies showing the effects of CHO mouth rinse on exercise performance

But… Why should I rinse my drink in the mouth and not drinking it straight away?

There are some ways to minimize the performance impairment of “training low”, which might be more necessary in athletes who engage in such approaches in a initial phase and that are not yet adapted to fatty acids oxidation during exercise. Ingesting caffeine appears to minimize the low carb performance impairment effect. Another suitable option is of course, carbohydrate mouth rinse. Many studies since the first work published in 2004 by James Carter have shown that CHO mouth rinse can improve performance when compared to a taste-matched placebo or even water.

Okay so, how should I do it?

The most common protocol is the 5-second mouth rinse in regular intervals where subjects must of course, spit the drink afterwards. Other studies have tried to set a dose-response effect of longer rinse duration of 10, and 15 second mouth rinse, but the limit so far appears to be on the 10 second-rinse VS the 5-second mouth rinse protocol. Still, caution should be exercised with rinsing for more than 10 seconds as suggested by Gam el al. (2013), since longer duration might affect normal breathing patterns and impair performance.

Our advice on Fuel the Pedal is, when the workout intensity allows for a light breathing pattern, give it a good 10-second rinse with that sugary beverage in your mouth before spitting it out (but do it in a chivalrous and classy manner, without hitting your teammate in the process). When your breathing is a little bit more heavy, try and guarantee at least the 5 second window or postpone the mouth rinse for a couple of minutes later, when the intensity lowers a bit. The ideal condition would be to rinse during each 5 to 10 minutes during the first 60 to 90 minutes of the session, preferably combined

What drinks can I use? I don’t feel like spitting out my isotonic drink!

Of course you don’t!  Using your isotonic drink to rinse and spitting it out it’s a waste of money. Why? Because mineral content plays no part in CHO mouth rinse effect. For the moment, it is known that glucose (maltodextrin)glucose-fructose (e.g. sucrose) mixes can do the trick and there seems to be no differences amongst them. Therefore, you might even want to use that opened commercial juice left in the fridge, or that sparkly soda that has no gas left in it. Honestly, just adding table sugar at a concentration of approximately 6% (e.g. add 30g of sucrose to 500ml of water) will do the trick and it’s the best cost-effective alternative.

Just don’t go around rinsing with “zero” versions of sugary beverages. Artificial sweeteners appear to be unable to produce the effects of carbohydrate rich drinks when mouth rinsed. Our brain appears to be smart enough not to be fooled by our artificial sweet creations.

Only for Training or for competition as well?

Let’s give the best universal answer for everything… It depends.

It depends on what? On training intensity and on race characteristics.
As we have mentioned before, cyclists engaging on workout routine that includes training low cycles on their calendar, can benefit from this approach so they can minimize the effects of impaired performance. In addition, cyclists who have low tolerance for food intake during or right before workouts might benefit from this approach as well.

If where talking about a typical mountain bike races, track cycling or even cyclo-cross where athletes start very explosively, breathing heavily and with absolutely no chance of taking their hands off the handlebar it is of course impractical to apply this strategy. Nonetheless, these events have very short duration to justify such strategy.

During a road race, especially a long endurance effort of more than 4h, while it could make sense to use a CHO mouth rinse strategy in the first hour where most riders aren’t attacking or pedaling at high intensities, using a CHO mouth rinse couldn’t be as beneficial since the positive outcomes are especially observed in the fasted state rather than in the fed state.

Bottom line

Carbohydrates are great! They are the ultimate fuel for cyclists and many other sports. In fact, they are so great that you don’t even need to ingest them. Only mouth washing them in your mouth can induce positive training benefits, especially during a “training low” strategies during workouts performed in the fasted state to further enhance training adaptations.
However, it is recommended that an Accredited Sports Nutritionist set up such a program so that athletes can obtain the full benefits of such strategy.

Just don’t forget to brush your teeth after working out.

FTP Team