The Hong Kong Journal of Sports Medicine and Sports

Volume XIII, November 2001

An evaluation of a popular sport beverage: gastric empyting and exercise responses

Robert N. Girandola
University of Southern California
Los Angeles, California, USA

Two experiments were devised. The first experiment was to determine the GE rate of two commercial sports beverages. One beverage was the ever popular GA. The other was called Miracle Sports Water (MSW). This drink is made of filtered distilled water, no sugar or calories, and a few minerals (Le, potassium, chromium). The second experiment was to compare these two beverages (as well as plain tap water (W) as a means of fluid replacement for subjects while exercising in the heat.

The results of the first experiment indicate that a fluid of low osmolarity (MSW) can empty of out of the stomach, after fifteen minutes, about 60% faster than GA, a popular replacement beverage. However, the results of the second experiment indicate, that despite this advantage, there are no differences in exercise performance or indices of thermal stress, at least in exercise of one hour at this intensity (50% of Max). GA is a replacement beverage that contains carbohydrate calories, as well as some minerals. As such, it is of value when energy requirement in exercise are substantial. However, in one hour at the current VO2, energy demands would only amount to about 300 Calories and thus GA has no major advantage. In fact, simple tap water (W) can maintain thermal balance to the same degree that a commercial beverage can! However, it should also be pointed out that subjects had to be “pushed" to consume the W, especially early in the exercise. Subjects had no problem consuming the GA and this may be a factor of taste as well as other factors associate with this beverage. The most important factor is that subjects consume fluid and under voluntary fluid ingestion conditions, the beverage of choice, is the fluid that the athlete prefers to drink.

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