The Heat Is On
Tuesday, July 27, 2010
Although travel is a rewarding and fun experience, jet lag, exotic foods, and long hours sitting on a plane or cooped up in business meetings can take their toll. Clearly, this is not the time to stint on exercise. But exercising in the summer heat, especially in an unfamiliar climate, requires special vigilance. Here are some guidelines. By Phyllis McIntosh.
It takes three to five days to adapt to a hotter environment, whether you are vacationing in warmer climes or simply spending more time outdoors instead of in an air-conditioned home and office, says Dr. William O. Roberts, professor at the Department of Family Medicine and Community Health at the University of Minnesota and former president of the American College of Sports Medicine. Exercising in the heat puts added stress on the heart, which must not only supply blood and oxygen to the muscles but also shunt blood to the skin where it can be cooled.
Know the heat index
Consider the combination of heat and humidity when deciding whether it is safe to exercise outdoors. Avoid it when the dew point approaches 80 or the heat index rises above 90. A good rule of thumb, says Roberts, is to avoid or limit exercise when heat (measured in degrees Fahrenheit) and humidity (in percentage points), combined, total 140 to 160.
Minimize heat exposure
By exercising in the shade, early in the morning or in the evening, you can cut down on your heat exposure. Activities such as cycling or in-line skating that provide good airflow, and thus increase the evaporation of sweat, are good alternatives to running in hot weather. When in the sun, always wear a hat and sunscreen; sunburn limits the body’s ability to cool itself.
The goal is to drink enough fluid to replace what you sweat out. Ignore recommendations that specify drinking a certain amount every 15 minutes or so, “because there’s a huge individual variability in fluid loss,” Roberts says, “and drinking too much can upset your sodium balance.” He advises drinking “as soon as you start to feel thirsty and as long as you still feel thirsty.” Water is usually the best choice; sports drinks add unnecessary—and expensive—calories. Roberts cautions that you can become dehydrated even when exercising in water, so be sure to maintain fluid intake during brisk swim workouts. Travel and exercise do go together, even in warm weather, as long as you use common sense, listen to your body—and the weather forecast—and keep the water bottle close by.
Author Bio: Phyllis McIntosh has 30 years of experience writing on health-related topics.