After you finish a hard workout, your top dietary priority should be to replace the fluids you lost by sweating so that your body can get back into water balance. Ideally, you should have minimized dehydration during the event by consuming at least 80 percent of sweat losses, but that can be hard to do during intense exercise. Hence, the best choices for replacing sweat losses include one or more of the following:
- Juices, which supply water, carbohydrates, vitamins, and potassium
- Watery foods such as watermelon, grapes, and soups that supply fluids, carbohydrates, vitamins, and potassium
- High-carbohydrate sports drinks or soft drinks, which supply fluids and carbohydrates (but minimal, if any, vitamins or minerals)
- Commercial fluid replacers, which supply fluids, some carbohydrates and sodium, and a few vitamins if fortified with them
- Water, which tends to be convenient, well tolerated, and least expensive
To determine how much fluid to replace, you need to know how much water you lose during a strenuous event. You can estimate this by weighing yourself before and after a hard training workout. Your goal is to lose no more than 2 percent of your body weight (for example, 3 pounds for a 150-pound person). By drinking on a schedule (eight ounces every 15 to 20 minutes of hard exercise), you can prevent or at least minimize dehydration.
One large, muscular man who spent two hours at the gym doing an hour of cardio and an hour of strength training was shocked to discover he’d lose about 8 pounds (3.5 kilograms) during the morning sessions-5 percent of his body weight and the equivalent of a -gallon (4 liters) of sweat! (One pound of sweat loss represents 16 ounces of -fluid.) He became aware of the importance of drinking more. He started bringing a gallon of water to the gym. He drank one quart every half hour and made sure that he finished the whole gallon. These steps to prevent dehydration helped him recover easily. Drinking large volumes of fluid during training will help you adapt to the fluid load and prevent stomach sloshing and discomfort during competitions.
If you become dehydrated during an unusually long and strenuous bout of exercise, you should drink frequently for the next day or two. Your body may need 24 to 48 hours to replace the sweat losses. You’ll know that you are adequately rehydrated when your urine is clear or pale yellow and you have to urinate frequently. If you urinate only a small amount of dark colored urine, it is still concentrated with metabolic wastes. (If you take vitamin supplements, your urine may be a dark color, so you’ll need to judge your hydration status by the volume of urine.)
Excerpted with permission from Nancy Clark’s Sports Nutrition Guidebook, by Nancy Clark, Human Kinetics Publishers, Inc.