If you're at least thirty-something, you can probably still remember your high school coach handing out salt tablets as part of the pre-game ritual. Those little yellow pills were supposed to replace the sodium lost in the perspiration process, but they probably contributed more to dehydration than anything. It's a miracle any of us survived.

Our technologically advanced kids and their coaches know better than to take salt tablets. Not only are they smarter and more sophisticated than we were, they also watch more TV. By now, ESPN and Michael Jordon have almost everyone convinced that it's virtually impossible to survive a quick game of hoops without throwing back a few sports drinks. But contrary to popular belief and the commercially endorsed testimonials of name brand athletes, you can exercise effectively and safely without them.The first of the popular sports drinks, Gatorade, made its debut almost 30 years ago when a few entrepreneurial types at the University of Florida came up with a million-dollar idea. They figured that if they analyzed the sweat of their Gator football players, they could design a drink that nearly equaled it to replace the body fluids and electrolytes lost during strenuous exercise. Because their concoction ended up tasting a lot like Gator sweat, they opted to disguise it with a little sugar and artificial coloring, and the rest is history. Gatorade and its wanna-be competitors have built a multimillion dollar empire.

Sports drinks are supposed to ward off dehydration and fatigue by maximizing the body's absorption of fluid and high-energy carbohydrates. To be effective, the sugars in a sports drink should be primarily glucose, the fuel your muscles use for energy. Ingredients like starch, maltodextrins, glucose polymers and glucose are best - they provide 100 percent glucose. Sugars like sucrose and high fructose corn syrup aren't as effective-they provide only about 50 percent glucose - but they do taste better.

The most popular sports drinks, Gatorade, Allsport and Powerade contain mostly fructose. Their relatively high sugar content holds them in the stomach and actually pulls body water into the gastrointestinal tract, away from working muscles. Because they require more digestion, the body absorbs them more slowly than plain water, and the full stomach they cause gives some exercising athletes a bellyache.

That salty taste you get with most sports drinks is just that - salt - made of sodium and potassium. These electrically charged minerals, called electrolytes, power your working muscles (including your heart) during exercise. Sports drinks include sweatlike proportions of electrolytes, but the truth is, most of us lose insignificant amounts during regular exercise, and it's not really necessary to replace them right away.

Short workouts lasting less than an hour don't deplete the body of minerals or electrolytes. These deficiencies develop over weeks or months, not after a jog around the block or a half-hour aerobics class. You can get all replacements you need from your next meal. After quick, intense bouts of exercise and sweating, you just need to replace fluids, and plain old tap water will do the job just fine, for pennies a serving.

If you're exercising to lose weight, sports drinks may not be for you. The 150 calories you worked so hard to rid yourself of can be almost effortlessly and instantly replaced by downing a 16-ounce bottle of your favorite sports drink.

Except for their labels and celebrity endorsements, most modern sports drinks are pretty much the same. And for all the sports drink hype, most people don't need them. Reasonably healthy people engaging in non-endurance types of exercise do just as well-or maybe even better-drinking plain old water.

If you exercise for more than an hour a day, congratulations. You deserve that sports drink, as well as the president's award for physical fitness. You also need to take your fluid replacement very seriously to avoid dehydration. Endurance athletes can lose several liters of water, as well as electrolytes in the form of sweat.

If you're going to drink sports drinks, you should follow proper sports drink etiquette.

For maximum effectiveness, they should be consumed at a rate of five to 12 ounces every 15 to 20 minutes during exercise. This provides a steady flow of fluid, energy and electrolytes to ward off dehydration and fatigue.

Sports drinks should be served chilled, and the last swallow should be chased with some water. Sports drinks are acidic, and when they're served warm or sipped, they're more likely to erode tooth enamel and promote cavities. Cold liquids are absorbed more quickly from the stomach, speeding fluid replacement and minimizing the discomfort that a full stomach can give you while you're exercising.

If your idea of exercise is the 15-yard dash from the couch to the refrigerator during halftime, you can save yourself some money, extra calories and tooth decay by drinking plain old tap water. But if you wanna be like Mike, and Gatorade does the trick, then by all means, drink it up!