can rinsing with sports drinks improve race performance

If you frequently participate in or watch marathons, you might notice a detail: some athletes often rinse their mouths with sports drinks during the race, and some even do so after passing the 40-kilometer mark. This action raises questions among many runners: with only six or seven minutes left to finish, is it really necessary to waste time and energy on this?

However, there is a specific purpose behind this action. Over the past decade, evidence has shown that rinsing your mouth with carbohydrate drinks can help improve your running performance. Today, let me explain how this works.

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Why does rinsing with sports drinks improve performance?

Theoretically, when you rinse your mouth with sports drinks, the carbohydrates don't actually enter your body or act on your working muscles. So how do they enhance your athletic performance?

In a study published in the Journal of Sports and Exercise Science, Canadian researchers had a group of cyclists perform a 2-hour steady-state ride followed by a 30-minute time trial. Using the 'sports drink rinse' technique, their performance improved by 2%.

The lead researcher of the study, Matt Jensen from the University of Victoria, explained: 'We know that food can trigger or even simulate emotions and perceptions, and carbohydrates are the main substances acting on emotions and perceptions. Therefore, even if the carbs are not actually absorbed, our body responds as if 'nutrients are about to enter the system.'

Studies have compared the brain's response to real sugar and artificial sweeteners. You might think that since artificial sweeteners are also sweet, the body would react similarly. However, that's not the case; the body only responds to real carbohydrates.'

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Can carbohydrates be absorbed that quickly?

Many of us have experienced mild hypoglycemia during long runs or on an empty stomach, feeling dizzy and weak. But if you eat or drink something sugary, you immediately feel better.

Can carbohydrates really be absorbed that quickly? There is a direct connection between our mouth and brain. When your mouth senses food, your brain immediately receives the signal that 'food is on the way,' and it 'tricks' the body into working harder.

Our brain always wants to protect us by minimizing muscle damage. So, once the brain believes 'carbohydrates are limited,' it starts to reduce muscle work. This is one reason why athletes' performance is limited when carbohydrate stores are depleted during endurance sports.

In a new study, all subjects underwent a two-and-a-half-hour cycling experiment: 2 hours of steady-state cycling followed by a 30-minute time trial, with the time trial performance as the reference. The subjects were divided into two groups, all having breakfast 2 hours in advance and consuming energy foods during the ride. They were then asked to rinse their mouths with liquid for 5 to 10 seconds and spit it out during the 30-minute time trial. One group used a carbohydrate drink, while the other used a non-carbohydrate placebo, with both liquids tasting identical—conducted without the athletes' knowledge.

The result was that athletes who rinsed with carbohydrate drinks performed 1.7% better overall, with the difference being most pronounced in the final minutes of the time trial.

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What is the significance of rinsing with sports drinks?

Let's return to the broadcast of a major marathon. A Kenyan elite athlete grabs a drink bottle in the last one or two kilometers, squeezes a couple of sips into his mouth, rinses, and spits it out, preparing for the final sprint to shake off the trailing competitors. At this point, this action can fulfill the 'promise of carbohydrates to the body,' even if the body doesn't have time to process them.

In the last 20-40 minutes of a race, replenishing carbohydrates is actually meaningless because there isn't enough time for them to be transported to the needed muscles. 'Rinsing' is essentially a 'trick,' and if this 'deception' can bring a 1.7% improvement, that's the difference between a marathon time of 3 hours 56 minutes and 4 hours flat.

More practically, in the final stages of a marathon, especially in hot weather, most of us are already 'waterlogged.' When you see a drink but feel your stomach is full, rinsing your mouth is a good option.