Falling temperatures can present a daunting challenge to even die-hard exercise enthusiasts, and they pose a special risk for people with asthma because cold air can trigger bronchial spasms.

But a few simple steps can help ease that risk, allowing asthmatics the freedom to run, ski or skate from December straight through March, experts say.

“Cold air is one of the common triggers for asthma, especially exercising in cold, dry air. One theory holds that if the air is cold and dry it can cause dehydration in the airways of the lungs, leading to their spasm,” explained Dr. Pramod Kelkar, a Minneapolis asthma specialist and a spokesman for the American Academy of Allergy, Asthma and Immunology.

Most people with chronic asthma will have a “flare” when they exercise - called exercise-induced asthma, a narrowing of the airways that makes it difficult for air to move out of the lungs. Other individuals appear to have a flare of asthma only when they exercise and do not otherwise have chronic asthma.

Symptoms can include coughing, wheezing, tightness in the chest, and prolonged and unexpected shortness of breath after about six to eight minutes of exercise. These symptoms are often worse in cold, dry air, according to the academy.

Wintertime colds and flu pose another threat. While people with asthma are no more prone to colds or flu than the rest of the population, their compromised airways mean “they have worse symptoms, and they can be much more miserable than the rest of us,” Kelkar said.

The best defense against colds and flu are frequent hand washing and getting enough rest, experts advise.

When it comes to exercising in the bracing air, simple precautions can go a long way to preventing asthma flare-ups.

Most important, people with asthma “should always take their bronchodilators with them before they go outside,” said Dr. Abraham Sanders, an asthma specialist at New York Presbyterian Hospital and the Weill Cornell Medical College, both in New York City.

“If they can also find a way to inhale humidified air during exercise, that’s so much better for them,” he said. “So, for example, swimming is really good; ice hockey may not be as good.”

Sanders and Kelkar have a few more asthma-savvy suggestions for staying safe in chilly conditions:

  * Warm up before exercise, cool down afterward. “That’s extremely important, because it may reduce some of the symptoms they can get with asthma,” Kelkar said.
  * Take medication as prescribed. People with asthma should do this even if they feel fine, especially before exercising outdoors. Kelkar suggests using a rescue inhaler 15 minutes prior to wintertime outdoor exercise, to help prevent symptoms. If asthma symptoms still occur, check with a doctor. Physicians can check to see if the patient is using his or her medication properly, or suggest alternative medications.
  * Dress warmly and in layers. Retaining body heat keeps airways warmer, too. Wearing a scarf over the mouth and nose can also cut the chill of incoming air.
  * Exercise sensibly. Skiing seven miles cross-country after a year spent on the sofa probably isn’t a great idea. Always check with a doctor before embarking on any strenuous exercise program.
  * Drink fluids. Hydration is important - try carrying a water bottle during outdoor wintertime workouts.

The colder months can be a winter wonderland for nearly all people with asthma, Kelkar stressed.

“Patients with asthma should continue to enjoy life as they feel,” he said, “doing whatever physical activity they want. There are so many good medicines available these days, asthma shouldn’t be a problem when it comes to restricting physical activity.”

More information

For more on asthma and exercise, visit the America Academy of Allergy, Asthma and Immunology.