Volume 13, Number 5: August 2005
Ask Dr. Nancy
Q: I may be making excuses about exercise, but summer heat is brutal. Is it ever too hot to exercise outdoors?
A: The short answer is yes. But most of the time, the right precautions can keep you moving outdoors. Besides, good workouts are possible under a roof as well as under the sun.
Extreme heat combined with high humidity does present risks for exercisers. The heart works harder, and the body's way of keeping its coolthe evaporation of sweatworks poorly. Sweat evaporates very slowly in water-filled humid air. Young people and the elderly are especially prone to overheating, so on very hot and humid days, they should exercise in air conditioning.
And everyone should follow some hot-weather guidelines. First, drink water, lots of it (see the box on this page). No matter how fit you are, take 10-14 days to acclimate to the heat. Use common sense: slow down, exercise for shorter times, or back off in the intensity of your workout. Your heart is already working harder; you don't have to.
Other practical choices are time and place. Switch to early morning and evening hours and to shady placeswalk and run under trees, not beside bare streets full of burning cars. Even better, get in the water. Swimming and water aerobicsor just walking in waterare excellent cardiovascular workouts.
Finally, come indoors. Join a gym or walk in the mall. Walking briskly in place while you are watching TV for two half-hour shows is a great way to get an hour of exercise in each day. Swing your arms or do jumping jacks to increase the exertion. You'll get to see your favorite shows and have a healthy amount of exercise in the comfort of your own home. The main idea is to do some exercise every day whatever the season.