Recently, new research was published which sheds a fascinating light on how energy drinks work. This research shows us, quite clearly, that there are some benefits to these sugary drinks even if they are spat out and not swallowed. Who would have thought that just the taste of an energy drink in the mouth is all that is necessary to light that fire for extra performance?
Writing in the latest issue of The Journal of Physiology, Ed Chambers and his colleagues not only show that sugary drinks can significantly boost performance in an endurance event without being ingested, but so can a tasteless carbohydrate – and they do so in unexpected ways.
It has long been known that sugary drinks and sweets can significantly improve athletes' performance in endurance events. But the question has always been, how? Clearly, 'sports' drinks and tablets contain calories. But this alone is not enough to explain the boost, and the benefits are felt even if the drink is not consumed. Nor does the sugary taste solve the riddle, as artificial sweeteners do not boost performance even when they are indistinguishable from real sugars.
Chambers and his fellow researchers prepared drinks that contained either glucose (a sugar), maltodextrin (a tasteless carbohydrate) or neither, and then carefully laced them with artificial sweeteners until they tasted identical. Trained athletes were then asked to complete a challenging time-trial, during which they rinsed their mouths with one of the three concoctions. That's right, they did not drink these beverages.
The results were striking. Athletes given the glucose or maltodextrin drinks outperformed those on 'disguised' water by 2 - 3% and sustained a higher average power output and pulse rate, even though didn't feel they were working any harder. The authors conclude that as-yet unidentified receptors in the mouth independent from the usual 'sweet' taste buds must be responsible. “Much of the benefit from carbohydrate in sports drinks is provided by signalling directly from mouth to brain rather than providing energy for the working muscles,” explained Dr Chambers.
The working theory now is that it is not the muscles, heart or lungs that ultimately limits performance, but the brain itself, based on the information it receives from the body. Stimulating the brain in certain ways – such as swilling sugary drinks – can boost output, perhaps giving athletes that all-important edge over their rivals.