The sports drink industry is quick to point out the benefits of carb-loaded, electrolyte-replenishing thirst quenchers, but plain old water also has a long history of staving off dehydration. Your individual tastes, the length of your run and the weather conditions where you're running should dictate which form of hydration will work best for you. For shorter runs, a simple bottle of water should do the trick. If you're running for more than an hour, or in particularly hot or humid weather, consider switching to sports drinks, which contain carbohydrates for energy and electrolytes to bolster hydration.
Once you've settled on your beverage of choice, you need to figure out how to transport it while you run. For shorter runs, you can simply carry your water or sports drink with you. For longer runs, consider wearing your water. Hydration belts have elastic loops that hold several small refillable bottles. Hydration backpacks contain a refillable rubber bladder with a tube that loops over your shoulder, letting you to sip on the go.
Sometimes even sports drinks aren't enough to keep your body properly fueled. In the next section, we talk about loading up on carbs before, during and after the race.