Children have lower sweating capacity than adults. They tolerate high temperature less efficiently. Frequent vomiting and severe diarrhea in infants and young children quickly can lead to water dehydration.
Older folks may be at increased risk for dehydration because their thirst mechanism may not be as efficient as at younger ages. The influence of medications and the presence of disease are other factors that affect fluid intake and water balance. For both the young and the old, encourage water intake often.
Of all nutritional concerns for athletes, the most critical is adequate water intake. The athlete’s immediate need for water is to control body temperature and to cool working muscles. Lack of water, above all other nutrients, has the ability to hinder performance and lead to serious complications.
Two to three percent fluid loss in a 150 pound individual represents three to four and a half pounds of body weight or one and a half to two quarts of lost water. Marathon runners and other long distance athletes may lose up to six pounds of sweat per hour.
To prevent dehydration during exercise, athletes should drink fluids before, during and after activity. Even exercise in cold weather results in sweat production and requires adequate fluid replacement. Although electrolytes, such as sodium, also are lost through perspiration, the immediate need is for water alone. In most circumstances, sodium and other electrolytes can be replaced after exercise. Seasonings, especially salt, on foods at regular meals usually will do the trick.
- During exercise or athletic events, thirst is not always a reliable gauge of fluid needs. The best approach is to go into the event with adequate fluid intake. Six basic tips for keeping fluid levels up during sports activities follow:
- Cool water between 40 to 50 degrees Fahrenheit is best.
-- Plain water is best. Sugar and electrolytes in fluids may slow emptying from the stomach.
-- Don’t depend on thirst. Drink ahead of thirst.
-- Drink water before a sporting or activity event. Two cups of water about two hours before an event is about right. Follow this with one cup of water about 15 minutes before the event.
-- Sip water during an event
-- Weigh before and after a sporting event or heavy workout. After the event, replace two cups water for every one pound lost.
Water balance in children involved in sports or physical activities is a special concern. Children have lower sweating capacity and less tolerance for hot temperatures. They need frequent fluid intake in order to regulate body temperatures. A water bottle or ready water supply should be handy during all sports activities.
The combination of hot, humid temperature and physical activity places outdoor workers at special risk for water balance. Anyone who works or plays hard outside, especially in hot weather, needs to keep water handy.
Sipping throughout the work period is better than saving up for scheduled meals or breaks. Pay particular attention when weather shifts from cool to warm, because it takes a few days for the body to adjust to the warmer temperatures.
Source: Linda Boeckner, UNL Nutrition Specialist
Ann Fenton
UNL Extenison Educator, Pierce County
