Exercise-induced bronchoconstriction (EIB), also called exercise-induced asthma, is a narrowing of the airways in the lungs that is triggered by physical activity.
EIB is common in patients with chronic asthma, who frequently experience flare-ups while exercising. But it can also occur in otherwise healthy individuals who experience asthma symptoms only when they exercise.
Symptoms of Exercise-Induced Asthma
If you have EIB, you may have problems breathing within five to 20 minutes after exercise. Symptoms of EIB are similar to those of chronic asthma, but the timing of the symptoms is closely linked with physical activity.
Your symptoms may include:
• Tight chest
• Shortness of breath
• Chest pain (rarely)
People with EIB are typically very sensitive to both low temperatures and dry air. Air is usually warmed and humidified by the nose, but during demanding activity people breathe more through their mouths. This allows cold, dry air to reach your lower airways and your lungs without passing through your nose, triggering asthma symptoms.
Air pollutants, high pollen levels and viral respiratory infections may also be triggers. Other causes of symptoms while exercising include being out of shape, poorly controlled nasal allergies or vocal cord issues.
An allergist / immunologist will begin by getting your health history, conducting a physical examination and performing a breathing test called spirometry.
If your breathing test shows that you might have asthma, your physician may give you a drug to inhale such as albuterol. If your breathing test numbers improve after inhaling the medicine, then the diagnosis of asthma is more likely.
You may be asked to take an additional test, called a bronchoprovocation challenge test. Your physician will have you exercise in the sport you play, run outside, or have you cycle or run on a treadmill. Before and after the exercise, your physician will test the amount of air you force out of your lungs with a spirometry test. If you exhale air less forcefully after exercise, the problem may be EIB.
Managing Your Condition
People with EIB are still able to exercise – and should exercise regularly. But you need to be sure that you are doing the right kind and right amount of exercise.
If you have been diagnosed with EIB, talk with your allergist before you begin an exercise program. Together, you can develop a management plan that will allow you to participate in activities with minimal asthma symptoms.
To prevent asthma flare-ups, your doctor may prescribe that you take an inhaled short-acting medication prior to exercise. These medications are effective in preventing EIB symptoms in 80 to 90% of patients.
Drinking water, warming up and cooling down and wearing a mask or scarf over the mouth when exercising in cold weather can also help minimize EIB.
Even the sport you choose can affect your symptoms. Swimming is considered less likely to cause asthma symptoms because the warm, humid environment of the pool does not aggravate the airways. Warm-weather activities and those requiring only short bursts of energy are also recommended. These include:
• Leisure biking
Because cold, dry air can make symptoms worse, as can activities that require continuous exertion, it is recommended that individuals with EIB avoid sports like:
• Cross-country skiing
If your child has EIB, talk with teachers and coaches to explain prevention strategies (such as a warm-up), warning signs of EIB and how medications are used. You should also provide a copy of your child’s asthma management plan.
Exercise is important and provides many health benefits, especially for people with asthma. So don’t give up on an active lifestyle.
Find out more about asthma.
This article has been reviewed by Andrew Moore, MD, FAAAAI