The cold is here. What happens to your body when you work out in lower temperatures?

You don’t have to be a hardcore fitness enthusiast to reap the benefits of outdoor exercise during the cold winter months. Just 20 minutes of outdoor aerobic exercise three times a week can help you maintain healthy lungs and avoid Vitamin D deficiency.

“Cold weather is not a free pass to spend November through March on the couch,” says Dr. Olugusen Apata, a pulmonologist, critical care physician and sleep specialist with Advocate Trinity Hospital in Chicago. “The body’s need for exercise and exposure to what we call the sunshine vitamin remains the same every month of the year.”

Winter sports like skiing, sledding and snowboarding are good alternatives to indoor and warmer weather cardio exercises that help strengthen the lungs.

“Contrary to widespread beliefs, inhaling cold air will not damage the lungs,” Dr. Apata says. “Because the air tends to be drier in colder temperatures, some people experience a cough, which fuels the cause for concern. But rest assured, the body has a way of warming the air before it reaches the lungs.”

But, Dr. Apata cautions that if you have asthma, COPD or any other hyperactive lung disease, extreme temperature conditions can precipitate an attack if the disorder is not well controlled.

“The important thing to remember about outdoor exercise is to drink plenty of water and dress warmly, preferably in layers,” Dr. Apata says, adding that it is equally important to avoid hazards and watch out for black ice or slippery surfaces that can cause you to slip and fall when exercising outdoors.

Although the body may not produce the same amount of sweat in cold weather, it burns as many calories as it does during warm weather workouts of the same intensity – which means the need to replenish fluids remains the same. Likewise, extremities such as the ears, fingers and toes are susceptible to frostbite, even when you’re feeling warm from your workout.

Dr. Apata says that if traditional winter sports are not accessible, outdoor running or brisk walking can help maintain lung health. He advises you to speak with your lung doctor if you have questions or any concerns.