Thirsty? If the answer to that question is yes, you may already be slightly dehydrated. Dehydration can be acute, from a hard practice or exercise session, or chronic, because of lack of sufficient daily fluids. Water is essential in many functions in the body. Digestion of foods, breakdown of nutrients, transportation of those nutrients, and elimination of body wastes are a few examples. Signs of dehydration include headache, light-headedness, fatigue, inability to concentrate, decreased physical performance, dry mouth, and dark, strong-smelling urine.
Thirst is not always enough to remind us to drink plenty of fluids. The environment can affect the thirst mechanism. Swimmers and water aerobic participants are under water during exercise. Often, they are not aware of the need to drink because of actual changes in the process in which thirst is triggered. Other environmental factors that increase fluid requirements include heat, high altitude, and low humidity.
How much do you need to drink? It is important to drink plenty of fluids all day, every day. In addition, drink about two cups (16 ounces) before a workout and about a cup every 20 minutes during your workout. According to Nancy Clarks Sports Nutrition Guidebook, after your workout, you should drink two cups of fluid for every pound you lose during a workout session, just to replace the water lost from a workout. (Remember, this is fluid loss, not body weight.)
Water is the best fluid replacement. For children and adults, water is adequate for a one-hour practice or workout. For longer workouts, a sports drink with some carbohydrates may be desired. Try to avoid caffeinated and alcoholic beverages, as those tend to be dehydrating.
Remember to drink plenty of fluids all day, not just when you are thirsty. Juice, herbal teas, soups, milk, and smoothies are other great beverages. Stay hydrated and stay active for good health!