A comparison of selected athletic drinks in their rates of gastric emptying
The intent of this study was to compare the rate of gastric emptying of three commercially available athletic drinks (GA, BT, and BP) against water, and in doing so to assess the exchange of water, carbohydrate and electrolytes 15 minutes after ingestion. Nine men and three women reported to the laboratory after having fasted for 12 hours.' A No. 20 French Levine Tube was inserted through the nasal passage and into the stomach. The subjects drank down 400 ml of the test solution containing 25 mg of phenol red which was used as a volume indicator. Fifteen minutes after ingestion, the gastric contents were aspirated via the tube by means of a 50 ml syringe. The 4 conditions were tested in one morning, with the order of feedings rotated between subjects. The recovered gastric contents were measured for total volume, volume of original drink, carbohydrate content and gastric electrolyte exchange. Student t values were used to test the difference between means set at the P < .05 level of confidence. BT and BP were found to empty statistically the same volume of fluid in 15 minutes as did water, while GA emptied 39% less volume than did water. BT, BP, and GA contributed 1.9, 4.5 and 6.8 gm of carbohydrate respectively in 15 minutes. These data are in agreement with previous findings that high glucose concentrations (GA - 4.5 gam) cause a slowing of gastric emptying.