Hydration important while exercising

Dehydration is a common problem among athletes and can potentially be a life-threatening situation. With the fall school sports seasons once again underway, it is important to understand how to stay adequately hydrated to prevent dehydration and to optimize performance levels.

Dehydration is critical when exercising in the heat, but dehydration can occur in any type of exercise setting, including exercising in cool weather or in water. Developing a hydration plan or protocol is critical for maintaining an athlete's health as well as providing the opportunity for optimal performance. This must also include a rehydration strategy that takes into account the individual athlete, the sport dynamic (are there rest breaks and are fluids provided at break?), environmental factors, acclimatization state, exercise duration, exercise intensity and individual preference. Just as a coach develops a game plan or strategy for playing the game, the athlete must develop a strategy for staying hydrated.

Dehydration during exercise occurs when an athlete loses more fluid than he or she takes in. An athlete will lose water through sweat, urine and respiration. The simplest method in checking hydration status is to compare urine color. Urine should be clear to light yellow in color when fully hydrated. A second method in determining hydration status is monitoring pre- and post-exercise weights. Comparing these weights gives a fairly accurate measurement of the amount of fluid lost during exercise. A rule of thumb is "a pint and a half a pound" which refers to the need to consume one and a half pints (24 ounces) of fluid for each pound lost during exercise.

Water should be readily available to athletes at all times during practice and game situations. This may mean planning ahead for the athlete or the parents. If water is not provided during practices, the athlete should always carry a thermos or cooler of water sufficient for the length of the event.

It is also important to check to be sure that the athlete is drinking fluids. Replacement by thirst alone is inadequate. If you are thirsty, you are already dehydrated. Sports drinks are recommended for exercise lasting longer than one hour. When drinking sports drinks, the carbohydrate (CHO) concentration should range between 4 percent and 8 percent. Anything over 8 percent actually disrupts stomach-emptying and causes gastric discomfort.

Early recognition of dehydration decreases the occurrence and severity of heat illness. Basic signs of dehydration are thirst, irritability and general discomfort, followed by headache, weakness, dizziness, cramps, chills, vomiting, nausea, and decreased performance.

If you follow the hydration guidelines listed below, you will decrease your chances of becoming dehydrated and risking the effects of heat illness. The following guidelines are from the National Athletic Trainers' Association (NATA) position statement and the American College of Sports Medicine (ACSM) position statement.

Hydration BEFORE activity:

Drink 17-20 ounces of water or sports drink two to three hours before event

Drink an additional seven to 10 ounces of water 10 to 20 minutes before exercise

Ingesting a balanced diet and fluids during the 24 hours preceding an exercise session is also crucial.

Hydration DURING activity:

Drink seven to 10 fluid ounces of water every 15 to 20 minutes

If exercising more than one hour, add a carbohydrate sports drink. CHO concentration should be 4 percent to 8 percent. Concentrations higher than this will slow the fluid absorption rate.

Hydration AFTER activity:

Following exercise, athletes should consume approximately 24 ounces of fluid (a pint and a half) for each pound of body water weight lost during exercise

If an athlete has a 2 percent or greater body weight loss compared to the previous day, he or she should be held out of practice.

Ideally completed within two hours, rehydration should contain water to restore hydration status, carbohydrates to replenish glycogen stores and electrolytes to speed rehydration

For questions about sports hydration issues, call Kris or Jodi at Point Sports Medicine Center at 715-346-5190.