Friday, April 24, 2009

Cutting Edge Research: A New Way to Drink Sports Drinks

For years, sports drink companies such as Gatorade® and Powerade® have extolled the benefits of their products. They argue that sports drinks can replenish energy, electrolytes and fluid lost during exercise. The scientific community has largely shown that this is in fact the case. Sports drinks can play a key role in the recovery from prolonged exercise. However, there may be an added benefit of sports drinks and athletes might consider a new way to drink them. A new study shows that these beverages may also have short-term effects on the central nervous system – but only if they are consumed correctly.
A group of researchers from Ghent University in Belgium examined whether or not simply rinsing the mouth with a sports drink affects endurance performance. Twelve trained cyclists participated in four exercise trials. For each trial they were asked to complete a certain amount of work in as short of time as possible. The trials were designed to last about 60min.

Before and during each trial, the athletes were given either a sports drink (Gatorade) or an artificially sweetened placebo. For two of the trials, they took in ~120ml (~4 ounces) of the beverage, rinse it in their mouth for 5 second then spit it out. For the other two trials, they drank an equal volume of Gatorade or placebo.

The time needed to complete the ride was significantly lower when the Gatorade was used as a rinse compared to when the drink was actually consumed. Under the sports drink rinse condition the cyclists completed the ride in 61:42 compared to a mean time of 63:16, an improvement of almost 4%. This occurred despite slightly lower blood glucose level and blood lactic acid concentration. It appears that simply rinsing the mouth with a sports drink for ~5 second causes a diminished perception of effort for a given exercise intensity. That is, the riders could exercise harder for the same degree of discomfort.

The researchers point out that actually drinking the Gatorade did not affect endurance performance while rinsing the mouth did. This is intriguing since most experts would have expected the opposite to be true. It also means that something must be happening in the mouth rather than that through digestion. It is possible that the carbohydrates in the sports drink interact with some sort of “receptors” in the mouth to stimulate the central nervous system. This effect might, in turn, improve the athlete’s effort and aid performance. While this is speculation on behalf of the researchers, there is some logic in their idea.

As for soccer players drinking sports drinks, it probably not advisable to rinse and spit as was done in this study. Ingesting both carbohydrates and fluids are critically important during recovery and for avoiding dehydration. However, athletes should consider that gulping their Gatorade may not be the best approach. The might try taking a drink, holding it in the mouth for 5 second before swallowing. This might maximize the short-term effects on the central nervous system as well as benefit from the long-term effects on energy storage and hydration. In the end, holding your drink in your mouth for a few seconds before swallowing might provide a small edge during the match.

References:

Pottier A, Bouckaert J, Gillis W, Roels T, Derave W (2008) Mouth rinse but not ingestion of a carbohydrate solution improves 1-h cycle time trial performance. Scandinavian Journal of Medicine and Science in Sports, DOI: 10.1111/j.1600-0838.2008.00868.x

Carter JM, Jeukendrup AE, Jones DA (2004) The effect of carbohydrate mouth rinse on 1-h cycle time trial performance, Medicine and Science in Sports and Exercise, 36:2107-2111.