Exercised-induced asthma is a narrowing of the airways in the lungs that is triggered by strenuous exercise. It causes shortness of breath, wheezing, coughing and other symptoms during or after exercise.
The preferred term for this condition is exercise-induced bronchoconstriction (brong-koh-kun-STRIK-shun). This term is more accurate because the exercise induces narrowing of airways (bronchoconstriction) but is not the root cause of asthma. Among people with asthma, exercise is likely just one of several factors that can induce breathing difficulties.
For most people with exercise-induced bronchoconstriction, treatment with common asthma medications and preventive measures enable them to exercise and remain active.
Signs and symptoms of exercise-induced bronchoconstriction may begin during or a few minutes after exercise, and they may persist for 30 minutes or longer if left untreated. The signs and symptoms may include:
- Shortness of breath
- Chest tightness or pain
- Fatigue during exercise
- Poorer than expected athletic performance
- Feeling out of shape even when you're in good physical shape
- Avoidance of activity (a sign primarily among young children)
When to see a doctor
See your doctor if you experience any signs or symptoms of exercise-induced bronchoconstriction. Because a number of conditions can cause similar symptoms, it's important to get a prompt and accurate diagnosis.
Get emergency medical treatment if you have worsening symptoms:
- Shortness of breath or wheezing that is quickly getting worse
- No improvement even after using a prescription inhaler for asthma attacks
Medical researchers are exploring several ideas regarding the cause of exercise-induced bronchoconstriction. There may be more than one biological process that can lead to the condition. Researchers do know that in people who experience exercise-induced bronchoconstriction, strenuous exercise sets in motion molecular events that result in inflammation and the production of mucus in the airways.
Factors that may increase the risk of the condition or act as triggers include:
- Cold air
- Dry air
- Air pollution
- High pollen counts
- Chlorine in swimming pools
- Chemicals used with ice rink resurfacing equipment
- Respiratory infections or other lung disease
- Activities with extended periods of deep breathing, such as long-distance running, swimming or soccer
Exercise-induced bronchoconstriction that is not treated can result in:
- A lack of beneficial exercise
- Poor performance in activities you would otherwise enjoy
- Serious or life-threatening breathing difficulties, particularly among people with poorly managed asthma