UAB Medicine

February 26, 2012

Beat the Heat - Tips for Summer Exercise

Hot and humid summer days can be tough to get through, especially if you love to spend time outside. To avoid heat-related illnesses and continue to do the things you love, whether it’s gardening, running, or playing sports, follow UAB cardiologist Dr. Alan S. Gertler’s stay-cool, heart-healthy tips.

What’s Happening to Your Body
Exercising on a hot, humid day is like a one-two punch to your heart, Dr. Gertler explains: “Physiologically, the heat of summer increases stress on the heart, particularly during exercise,” Dr. Gertler says. “Exercise and the air temperature increase core body temperature, and high humidity complicates the situation further because sweat doesn't easily evaporate from your skin. Your body responds by diverting more blood to the skin to cool itself, which results in less blood flow to the muscles and consequently an increase in heart rate.

Know the Signs—and What to Do
Warning signs of a heat-related illness can include:

  • muscle cramps
  • nausea and vomiting
  • weakness
  • headache
  • dizziness
  • confusion
  • irritability
  • body temperature above 104 degrees, a sign of heat stroke
  • cold, clammy skin, also sign of a heat stroke

If you experience these symptoms while outdoors, stop what you’re doing and get out of the heat, Dr. Gertler says. “Drink plenty of fluids, either water or a sports drink, and remove extra clothing and wet down your body with cool water, either in the shower or with a cloth. If symptoms don't improve after 30 minutes—or if you exhibit heat stroke symptoms—seek medical attention immediately.”

3 Summer Exercise Secrets
Scorching days don’t mean you can’t enjoy the great outdoors. “If basic precautions are followed, most heat-related illnesses can be prevented,” Dr. Gertler says. The three secrets to exercising during summer’s scorching days are hydration, timing, and the right clothing.

  • Hydrate, Hydrate, Hydrate

Drink eight - 12 ounces of water 30 minutes prior to exercise, plus six to ten ounces for every 30 minutes of exercise. Sports drinks are recommended for exercise sessions exceeding an hour.

  • Timing Is Everything

It is best to exercise in the early morning or evening hours, when the temperatures are cooler and the sun is not as strong.

  • Dress Right

Remember to dress appropriately—avoid dark colors, and wear loose-fitting cotton T-shirts, shorts, and a brimmed hat. Always wear sunscreen.

Be Heart Smart
“Monitor your heart rate while you exercise, and stay within the range prescribed by your doctor,” Dr. Gertler says. “If you have an underlying heart problem, talk to your doctor before exercising in the heat.”

For more heart-healthy tips, visit