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Mouthwash To Improve Performance:
Evidence for the Governor
Written by Dr. SkibaRecently we have discussed the concept of the central governor. Briefly, this is a theory that suggests that athletic performance is more than just the sum of the ability of the heart and lungs and muscles. Proponents of the central governor hypothesis believe that there is a central mechanism in the brain that assists in planning performance. In other words, your brain decides what the best/safest strategy is for your to conduct a specific task (i.e. an hour long time trial) and to some extent orchestrates your performance, irrespective of what your conscious mind wants. The paper up for review today discusses some interesting findings regarding sports drinks / carbohydrate supplementation during exercise, and a link to this possible central governor.
First of all, many studies have shown that consuming a sports drink during exercise improves performance. Shame on you if you aren't slugging down the -ade of your choice during training/racing events longer than an hour. During long, moderate exercise, it has been shown that replacing carbohydrates this way keeps more fuel around, and increases performance and time to fatigue. However, there is some question as to whether replacement is necessary in shorter, higher intensity exercise, since you are probably only burning about 15 grams of what you drink in the first hour. (To give you some idea of what that means, a 150 lb. person should be consuming about 75 grams of carbohydrate per hour). Thus, we can't just say that consuming something sweet is improving your fuel stores, because you only burned 20% of what you took in that hour! Furthermore, in experiments where athletes are given a similar amount of sugar by IV, there is no benefit seen in performance. So, the $64,000 question is this: Why should drinking something sweet make you faster, but delivering sugar to your muscles more directly by IV not make you faster?
To answer this question, a couple of guys named Carter, Jeukendrup and Jones designed a pretty cool experiment. Wondering if it was the brain that sensed carbohydrates in the mouth and increased exercise performance, they had cyclists use a mouthwash during an indoor TT. It contained a non-sweet carbohydrate. This to some extent helped eliminate the placebo effect. The cyclists sometimes got the carb-mouthwash, and sometimes got water. They were not told which was which, or what was in either, but were told that both had been shown to improve exercise performance.
Interestingly, the study found an improvement of about 3% when the athletes used the carbohydrate mouthwash. The average time to complete the event dropped from 61.37 minutes to 59.57 minutes. Why? The investigators suggest that the carbohydrate is sensed by receptors in the mouth, and stimulate reward/pleasure centers in the brain. Another possibility is the "mouth-feel effect", that is, since some people were able to tell the difference between the placebo and real mouthwash, this could have provided the stimulus to the brain. Either of these possibilities could involve communication with a governor mechanism in the brain, which assumes that fuel entering the mouth will eventually get to the muscles, and then decides that it is possible to increase the workload without fear of running out of fuel.
Further study is needed in this area, of course...but our goal is to be faster, and not necessarily just science-geeks. Based on these results, I'd suggest drinking your Gatorade even in short racing/training sessions. We can leave it up to the scientists to hack out the how and why.
Reference:
Jones et al. The effect of carbohydrate mouth rinse on 1-hour time trial performance. Med. Sci. Sports Exerc. 36(12): 2107-2111. 2004.
