Is It Too Hot To Trot?

When the first warm, sunny day of spring arrives, you're rarin' to take your exercise program back to the great outdoors.

Whoa, hold your handlebars. If you're not careful, you could wind up with a case of heat exhaustion just as easily as the couch potato next door, no matter how fit you might be.

Indeed, although being fit increases your tolerance to heat and cold, your body still needs time to acclimate itself to warm weather. In winter, your body has had a relatively easy time exercising and keeping cool at the same time. But when temperature and humidity go up, your body has the added task of ridding itself of heat.

Fill the tank

Be sure to fill up on plenty of water for hours BEFORE you plan to head out for your first run in the sun. You can lose between two and five quarts of fluid an hour when exercising in hot weather. Drinking six to eight glasses of water throughout the day helps prevent dehydration during exercise. Drink a glass about an hour before exercise, and then whenever you feel thirsty. The exception is during very long exercise, such as a marathon, when you should also consume electrolyte replacement drinks to avoid sodium deficiency (hyponatremia). 

Take it easy for a while

Cut back on the intensity and duration of your workouts. Start out at about half-intensity and don't resume normal workouts for at least two weeks. This gives your heart enough time to increase its ability to supply your muscles with nutrient-laden blood while also diverting some to the skin surface, where it can help radiate excess heat to the air.

Timing is important

Exercise during the cooler parts of the day, such as the morning and evening. This is especially true if you live in the northern climes and take a February vacation in the Virgin Islands. Chances are you won't be there long enough for your body's cooling mechanisms to make any meaningful changes. It's a good idea to avoid intensive exercise anytime the temperature or the relative humidity is very high. High humidity, in particular, makes it harder for sweat to evaporate and take heat away from your body.

Be alert

If, despite following these tips, you begin to feel fatigued, feverish, or dizzy, stop exercising immediately. These could be the early symptoms of heat illness and could lead to more serious complications, such as heat exhaustion, or even heat stroke, if left ignored.