Athletes should never ignore the following warning signs of dehydration:

  • Thirst
  •  Weakness
  •  Irritability
  •  Dizziness
  •  Headache
  •  Nausea
  •  Decreased performance

Depending on your muscle mass, water makes up 55 to 70 percent of your body weight. Water is essential for cooling the body, digesting and absorbing food, transporting nutrients, cell building, removing waste products and improving circulation.

Dehydration is the number one nutrition-related reason for poor performance and can lead to heat-related illness. That’s why good hydration -- getting enough fluids and maintaining your body’s fluid level -- is so important.

Athletes Lose Water Weight Rapidly

When athletes sweat, they lose water that must be replaced. During an hour of exercise, an athlete can lose between two and five pounds in water weight, which can lead to moderate dehydration. To determine your sweat rate, weigh yourself before and after you exercise. Drink 20 ounces of fluid (a little more than two cups) for every pound you lose.

Before a workout:

  • Drink 16 to 20 ounces (two or more cups) of fluid one or two hours prior to exercise

During exercise:

  • Take drink breaks every 20 minutes, especially if you are exercising for longer than an hour
  • For workouts lasting more than an hour, drink fluids containing salt and carbohydrates. Sports drinks are a great source of both nutrients. Sodium (also known as an electrolyte) is important because it affects fluid balance in the body. Carbohydrates give you energy.
  • Don’t use thirst as your guide. Be sure to drink before you begin to feel thirsty.

After workout:

  • Drink 20 ounces of fluid for every pound you lost during exercise
  • To prevent muscle breakdown, try to replenish lost fluid within the first one-half to two hours after training
  • Use sports drinks and chocolate milk after training because they help replace some of the muscle energy stores almost immediately
  • To determine whether you are hydrated, check the color of your urine. Your urine should be pale yellow.

More hydration tips for athletes:

  • Have fluids close at hand during all training sessions and competitions. Some runners wear a belt that holds water bottles
  • Avoid caffeinated beverages. Caffeine acts as a diuretic, which can cause you to lose fluids and may contribute to dehydration.
  • Choose sports drinks wisely. Look for drinks that have less than 19 grams of carbohydrates per eight ounces of fluid. A high sugar content can delay the absorption of water and may cause dehydration, nausea, or cramps. Also, experiment with different brands of sports drinks during practice rather than trying them for the first time during an event or competition.