Well, sort of . Research shows that drinking fluids with the right mixture of carbohydrate (sugar) and sodium can increase the speed at which fluid is absorbed from your intestines into your body. It's part of the reason sports drinks are formulated the way they are. The trouble with a do-it-yourself sports drink like apple juice and water is that it's very difficult to get the ratio of sugar to water to sodium right, and if the ratio's off, your homemade sports drink could end up slowing fluid absorption instead of accelerating it.
What's so special about sports drinks? Across the board, a six-to-eight percent solution of sugar in water is widely accepted as the optimal mixture. To get there, different brands use a variety of sugars, and new research indicates that the best of them use a mixture of glucose and fructose that has been shown to increase the amount of carbohydrate that can reach your muscles while you're exercising. Sports drinks also contain sodium because you need to replenish electrolytes lost through sweat, and because sodium helps to drive a person's urge to drink.
The drive to drink is an important consideration for a sports drink because the whole point is to get enough fluids, carbohydrates, and sodium into your body to support your activity level and keep you hydrated. People stop consuming drinks that are too sweet, syrupy, or strong too early. By keeping the flavor light, cutting the sweetness, and including the right amount of sodium, companies like PowerBar have created formulas that outperform do-it-yourself sports drinks in providing energy, replenishing electrolytes, and speeding fluid into your thirsty body.