Asthma
When Exercise Makes Asthma Worse

Sitting on a gurney in the emergency room, Bruce looked very worried. Recently divorced at 35, he decided to get in shape and lose those 20 pounds that he had gained since college. He bought a pair of the latest ergonomically correct running shoes, a pair of ventilated track sorts and set out to run off the weight. He felt pretty good for the first ten minutes, then his chest became tight and he found it difficult to breathe. By the time Bruce saw his doctor, he felt fine. But when he tried running again, the symptoms recurred. Because he was now also complaining of a cough, I was called in to take a look.

Talking to Bruce, I learned that he had seasonal allergies to ragweed and his mother had asthma. Further pulmonary tests confirmed my suspicions: Bruce had exercise-induced asthma.

Exercise-induced asthma (EIA) is a narrowing of the airways following physical exertion. About 90 percent of people with asthma experience these symptoms to some degree. For people like Bruce, it can be the first time they realize an asthma problems exists. Fortunately, EIA is one of the most preventable and treatable forms of asthma. Interestingly, about ten percent of people without asthma will develop similar symptoms after exercise.

Causes of Exercise-Induced Asthma
While doctors do not fully understand the precise mechanisms behind EIA, a number of key factors have been identified. We realize that the temperature and the moisture of the air we breathe when it is inhaled through the nose is important. During exercise, we tend to breathe through the mouth, rather than the nose where it would be hydrated and warmed to body temperatures before reaching the lungs. As a result, the air is dry and and cool when it reaches the airways leading to airway irritability and constriction.

To make matters worse, when we breathe in through our mouths, we gulp in large amounts of pollutants that are suspended in the air. Doctors suspect that this increased level of environmental irritants also may trigger hyperactive airways.

Simple Solutions to a Complex Problem
Fortunately, exercise-induced asthma responds well to a range of treatment strategies. Simply wrapping a scarf over your nose and mouth in cold weather may be all you need to avoid EIA. In the summer months, a small facemask will serve the same purpose. Changing the type of sport can also be beneficial. The warm humid conditions of swimming are less likely to cause EIA than running or cycling.

Medication can also prevent the arrival of asthma symptoms. Many patients use their fast-acting inhalers before beginning exercise or sports. Normally we call these rescue medications, but when used with EIA, we view them as preventative therapy. A quick puff before exercise will stabilize the cells that release inflammatory compounds, preventing their release into the lungs.

Return to Top