Saturday, July 26, 2014

Does mouth rinsing with carbohydrates boost exercise and sports performance? By Jerry Brainum

Carbohydrates are the most efficient fuel for exercise. While certain amino acids from protein can be converted into glucose, which is the only sugar that circulates in the blood, the conversion of protein or amino acids into glucose is an inefficient process that doesn't yield much glucose. As for fat, only the glycerol portion of the triglyceride structure can be converted into glucose in the liver. Thus, only 10% of fat is capable of being converted into glucose. Carbs are considered the high test fuel to power both exercise and sports. Studies show that carb intake consistently improves performance in activity lasting more than 2 hours. It does this by maintaining glycogen stores, which are the primary fuel for anaerobic exercise, including bodybuilding exercise, and also enhancing carb oxidation, as well as maintaining a high energy level throughout the course of exercise or sports. When it comes to exercise lasted an hour or less, carbs aren't as vital. Studies have even shown that ingesting carbs prior to a high intensity weight workout does not contribute to the intensity level. But this also depends on the existing muscle glycogen state. With a depleted glycogen state, as occurs with a zero carb diet, ingesting the equivalent of one gram of carb per minute does boost intensity level during training.
    Some studies suggest that you don't even have to ingest carbs to provide an ergogenic effect. Merely rinsing the mouth with a carb solution for a few seconds is enough to boost energy and exercise performance. One study showed that cyclists who rinsed their mouths with carbs showed a 2.9% improvement in performance. Other studies have shown similar results with running.
    Why would just rinsing the mouth with carbs provide an ergogenic effect?  Some suggest that rinsing the mouth with carbs activates neural pathways that lower the perception of effort during exercise. A study published two years found that carb mouth rinsing didn't affect strength performance. A new study examined the effects of carb mouth rinsing during multiple sprints, which is a high intensity activity. The study subjects consisted of eight trained men, all with athletic backgrounds. The average age was 21. Anyone who had used creatine supplements, which would affect the outcome of the study was eliminated if they had ingested any creatine within 12 weeks of the study onset. The subjects were also asked to refrain from ingesting any caffeine and to ensure that they were fully hydrated to prevent dehydration-based interference.
     The men rinsed their mouths with either a carb solution composed of maltodextrin 6.4% or a placebo. They rinsed their mouths for 30 seconds before engaging in various sprint tests. The results show no improvement in sprint times, perceived exertion, or blood glucose levels in the men that rinsed with the carb solution. As such, the conclusion of the study was that mouth rinsing with carbs is not an effective ergogenic aid. It short, it just doesn't work.

Darling JK, et al. Effect of carbohydrate mouth rinsing on multiple sprint performance.J Int Soc Sports Nutr 2013: 10:41.

©,2014 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

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