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Keep Your Fitness Cool: Exercising in the Heat

Try these tips to work out safely when it's hot outside

Hydration Not the Whole Answer continued...

To determine your sweat rate, weigh yourself nude before your workout, then towel down and weigh again. The difference in ounces is the fluid you lost. "Replace that, not twice that," Roberts says. "Too much fluid can be bad, too."

McCauley, on the other hand, recommends drinking a quart before running or exercising outside, and a quart after. "Drink even if you are not thirsty," she says.

What about salt tablets? "They got a bad rep because they were thought to contribute to high blood pressure," Roberts explains. However, he still recommends augmenting with salt. "You know when you first exercise and the sweat drips in your eyes and it stings?" he asks. "Well, after two or three weeks of exercising in the heat, your salt level will go down. So I recommend eating a few more salty foods, pretzels, potato chips, or salt your food."

Time and Place for Exercise

How can one exercise smarter?

  • Run only between 4 a.m. and 6 a.m., McCauley says. That's when traffic is lightest and air quality the best. Sucking in poison to overload your already taxed system is not a good idea. Pollution of over 0.15 parts per million usually warrants an advisory -- so be advised! Be especially careful in cities with the worst ozone pollution. For 2003, according to the American Lung Association, they are (in order) Los Angeles; Fresno, Calif.; Bakersfield, Calif.; Visalia-Tulare-Porterville, Calif.; Houston; Sacramento, Calif.; Merced, Calif.; Atlanta; Knoxville, Tenn.; and Charlotte, N.C.
  • Wear light-colored, loose, absorbent clothing (lose the Spandex or even cotton, which can stay wet).
  • Don't engage in strenuous workouts, even in a heated pool (you can get overheated and dehydrated in water.)
  • Carry a frozen water bottle in the back of your shorts (feels good, too).
  • Seek shaded pathways.
  • Exercise moderately -- 60% to 70% of maximum heart rate. Take breaks. Walk.
  • Drink a couple of cups of room temperature water before leaving and more when returning. In between, slug back a cup or two every 20 minutes.
  • When it's over 90 degrees, hit the gym instead.

What to Do If the Heat Gets You

Despite all your care, what if the heat sneaks up on you or a companion anyway?

You need to cool off fast! "I toss my athletes in ice water," says Roberts. Cool, wet cloths, sips of water, shade, and if the person is still fire-hot or raving and incoherent, call the paramedics. "The idea is to lower the temperature as quickly as possible to stop the cooking process," Roberts says. "Temperature vs. time."

The best thing, however, is to prevent trouble. "I still see people in dark clothes running along a roadway during evening rush hour," McCauley says with a sigh.

"You can't get some people to do anything smart," Roberts says.

Reviewed on April 08, 2005

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