SUNDAY, Aug. 19, 2001 (HealthDayNews) -- Whether you're a serious athlete or simply someone who enjoys outdoor activities, make sure the dog days of summer don't put the bite on you.
The combination of physical exertion and hot, humid weather can pose a serious threat to your health if you fail to drink enough water to keep properly hydrated. If you don't, your body can lose water and essential elements and you run the risk of kidney problems -- or even death.
The recent heat waves that swept the country sent death rates rising. Deaths included that of Minnesota Vikings lineman Kyle Stringer, who died from heat stroke.
"Be aware that it's potentially a dangerous situation," says Dr. Edward Wojtys, director of sports medicine for the University of Michigan Health System.
When temperatures exceed 75 to 80 degrees and it's humid, it's easier to become seriously dehydrated. And it's important to recognize the signs of dehydration, he says.
They include an uneasy feeling and a noticeable decrease in energy and performance levels. You also may get a headache and your body may ache.
If you don't heed those signs, your body temperature can rise, and your perspiration, which acts as a cooling mechanism, may slow down or stop. You then could pass out.
It's important that you not wait until you feel thirsty before you take a good swig from your water bottle, advises Barbara Baldwin, information services director for the American Running Association.
"Often when you exercise, your thirst mechanism is suppressed so you would not even know you're thirsty," she says. "By the time you feel thirsty, you're already dehydrated."
You need to drink about 17 to 20 ounces of fluid two hours before you exercise to make sure you've topped off your tank, Baldwin says. And while exercising, you should drink 7 to 10 ounces every 10 to 20 minutes, and then drink about 20 ounces within two hours after you exercise.
What you drink is important, too. Soda and iced tea are bad choices, and fruit juices take too long to be absorbed by your body.
"Water is the best bet across the board," Wojtys says. "We think many of the sports drinks with the additional electrolytes and things are good, but not always necessary."
Baldwin suggests you consider a sports drink if you're doing high-intensity exercise or if you're exercising for at least an hour at a time.
One way to judge whether you're drinking enough while you exercise is to weigh yourself before and after your activity, Wojtys says.
"Go through a good workout in the warm, sunny weather and
drink fluids right through," he says. "And [if] your weight stays about the same, then you're doing a good job."
A loss of 1 to 2 pounds from a rigorous workout is OK. But if you lose 7 to 10 pounds and don't regain it overnight by drinking and eating, you'd better start guzzling.
Most likely what you've lost is water, Wojtys says. If you go back out to exercise again the next day and you're still dehydrated, it's more likely you're going to get into trouble, he says.
Baldwin says another way to gauge your hydration is by the color of your urine. If you're getting enough fluids, your urine should be a light color.
What To Do
If you're a coach or parent of children playing soccer, baseball or any other outdoor summer sport, you need to ensure the youngsters get enough fluids, Baldwin says. Children need to drink 4 to 8 ounces of fluid before they begin their activity and then drink 5 ounces every 20 minutes while playing their sport. When they're done, they need to drink 16 ounces of fluid for every pound lost while exercising.
For more information on exercising in the heat, take a look at a brochure from the American Running Association.
And for more on the dangers of dehydration, go to KidsHealth.com.
