Chris Froome was recently victorious in the prestigious Tour De France championship… for the SECOND time, and all this whilst getting abuse from crowds, including urine thrown into his face. You will be pleased to know that you don’t need to rinse your mouth with urine (unless you want to….weird).
If you watched the Tour De France at all, then you might have noticed some riders swilling their mouth with a beverage, only to spit it out on the road! Wasteful right? Nope, let me explain! This beverage could have been plain old water, or it could have been a specially formulated isotonic drink containing carbohydrate and electrolyte…also known as an isotonic drink. It’s understandable how some deem this to be a little wasteful, but it’s anything but, the cyclists are actually utilising a technique known as the ‘mouth rinse’.
Why rinse and spit?
Sipping a drink with energising carbohydrate and electrolyte only to spit it out again, does seem completely counterintuitive, I admit that. If you only want to moisten the mouth and refresh yourself then why not do this with water, why waste a scientifically developed energy drink? Well, one of the main complaints a Tour rider has is gastrointestinal distress AKA an upset stomach, this can come on for a number of reasons, but the main reason is too much fluid, and too much carbohydrate. Your body can only metabolise around 100g of carbohydrate an hour, so too much too soon could have catastrophic repercussions on the riders performance.
How does this work?
Carbohydrate is your bodies preferred energy source, that’s a known and accepted fact, it is critical for the production of ATP, your body’s main energy currency. Carbohydrate can deliver energy directly by being broken down to glucose and ATP, but it can also provide energy via more indirect methods.
Your mouth contains multiple carbohydrate receptors but no absorptive sites, this means that your mouth is able to send a message to the brain confirming that it is going to be receiving some carbohydrate and energy. This, however, is a blatant and ingenious trick that you’re playing on your poor unsuspecting brain, because seconds later you spat that carbohydrate onto the French tarmac.
So your brain is content in the knowledge that it is going to be getting some energy, and it will, just not in the form of the carbohydrate you had in your mouth.
The presence of carbohydrate in the mouth prompts your brain to trigger a process known as glycogenolysis, this breaks down glycogen (stored glucose) so that it can be used for energy. The insula/frontal operculum, the orbito frontal cortex and the striatum areas of the brain received signals to say it was getting more carbohydrate, which meant it felt happy to release some of its glucose stores because they would soon be topped up again.
When to do this?
You might have noticed athletes doing this mid race purely to refresh their mouth, but the main time to perform a mouth rinse is towards the end, during the last few miles of the event. You don’t want to prompt the release of too much glycogen too early on if you still have 80 miles of a 100 mile day left, but as you are running on fumes right before the finish, then a good final hit of glucose is just what you need.
Check out the EZ Fuel Supplement range for a cost effective and nutritionally dense selection of energy and isotonic drinks.
Jeukendrup, A. (2013), Practical limitations of ingesting large amounts of carbohydrate during exercise. Sport Nutrition Conference.