Exercise - Asthma Triggers: Asthma

Content provided by the Faculty of the Harvard Medical School

Exercise

Virtually everyone with asthma will experience some degree of bronchial constriction during or following exercise if the level of physical exertion is sufficiently intense. Even so, it is important to exercise on a regular basis. Not only is exercise good for your overall health, but some people with asthma find that getting into good physical shape can make breathing easier.

Exercise triggers asthma symptoms because it forces you to breathe more deeply and heavily than you do when you are at rest. As large volumes of air are drawn through the bronchial tubes and deep into the chest, the bronchial tubes give up heat and moisture to warm and humidify the incoming air. This causes the bronchial tubes to cool and dry out. The bronchial muscles contract in response, narrowing the airways and making it difficult to breathe. Although exercise in any climate can trigger asthma symptoms, cold, dry air is the strongest stimulus to bronchial narrowing.

If exercise brings on your asthma symptoms, it may indicate that your asthma is not well controlled, and you may need to step up controller therapy to reduce your exercise-related symptoms. If you still experience exercise-induced breathing problems even though your asthma is otherwise well controlled, or if the only time you experience asthma symptoms is when you exercise, take a medication before exercising to block bronchial muscle constriction. You can take a quick-acting bronchodilator, such as albuterol or pirbuterol, 5 to 10 minutes before exercise. Alternative preventive treatments are leukotriene modifiers or cromolyn.

A variety of other strategies are also effective in preventing an asthma attack after exercise:

• Exercise indoors, where the climate is controlled.

• On a cold day, wear a cold-weather face mask or wrap a scarf around your mouth and nose to trap a little bit of warm, moist air in front of your face.

• Warm up before exercising; this often helps to reduce symptoms.

Last updated:	September 27, 2007