What Is Exercise Induced Asthma (EIA) or Exercise Induced Bronchoconstriction (EIB)?
Exercise induced asthma is bronchoconstriction and asthma symptoms that develop when you exercise. It occurs in 7% to 20% of the general population.
While you have probably heard of exercise induced asthma before, your asthma care provider probably refers to it as EIB. Asthma doctors prefer the term EIB over exercise induced asthma because exercise is not a risk factor for asthma, but exercise can be a trigger of your asthma.
What Are the Symptoms of Exercise Induced Asthma?
The most common symptoms in exercise induced asthma are shortness of breath, chest tightness, and cough. Symptoms may occur shortly after a brief episode of exercise or 10 to 15 minutes into a longer period of exercise. Symptoms typically resolve with rest in no more than 30 to 60 minutes.
Symptoms of exercise induced asthma occur more commonly and are more severe in cold weather.
How Is Exercise Induced Asthma Diagnosed?
In known asthma patients with typical symptoms during or after exercise, your physician will often make a presumptive diagnosis of exercise induced asthma by discussing your symptoms with you. Many times your doctor will not obtain further diagnostic tests unless your symptoms persist, or they are not prevented by with some of the measures outlined below.
If you do not have an asthma diagnosis but develop shortness of breath, chest tightness, and cough during or after exercise, further investigation is indicated to make sure the symptoms are not due to some other condition like heart disease.
Most commonly a form of exercise testing with pre- and post-exercise spirometry is used to confirm a diagnosis of exercise induced asthma. Generally, you will exercise on a treadmill or stationary bicycle until you reach 85% of your expected maximum heart rate. You are considered having exercise induced asthma if your FEV1 falls more than 10% with exercise. Some asthma care providers may recommend a bronchoprovocation challenge test, but this is not specific for exercise induced asthma. Similarly, measuring peak flows pre and post exercise are not recommended to diagnose EIB because results are often inaccurate.
Other causes of the shortness of breath, chest tightness, and cough occurring with exercise also need to be considered. This is especially important if you have no other asthma symptoms and do not benefit from some of the preventive measures outlined below. Other diagnoses your doctor may consider include:
How Can I Prevent Exercise Induced Asthma?
If you have poorly controlled asthma and symptoms with exercise, treating the poorly controlled asthma may be the most beneficial strategy for you.
Exercise induced asthma can generally be prevented using one of the following inhaled medications:
- Rapid-acting bronchodilator: Using two puffs of a rapid-acting rescue medication like albuterol or formoterol 10 minutes before exercise may prevent exercise induced asthma symptoms.
- Cromolyn sodium (Intal): Cromolyn sodium can also be used for the prevention of exercise induced asthma and may be used in combination with a rapid-acting rescue medication.
For children and adults who who may exercise intermittently during the day and are not able to take a medication before each activity, a long-acting bronchodilator (LABA) or leukotriene inhibitor may be used.
- Long-acting bronchodilators: LABAs like salmeterol and formoterol, while not recommended as sole treatment for asthma, can be used for EIB. Salmeterol and formoterol should be taken 30 and 5 minutes, respectively, before exercise. Neither should be more frequently than every 12 hours.
- Leukotriene inhibitors: Leukotriene inhibitors like montelukast (Singulair) and zafirlukast (Accolate) can be used to prevent EIB symptoms in patients who need a longer period of protection or have a problem using inhalers.
What Do If I Still Develop Symptoms of Exercise Induced Asthma?
If you develop wheezing symptoms or bronchoconstriction after beginning exercise or forgot to take medication prior to beginning exercise, you will want to use your rescue inhaler and follow your asthma action plan.
Sources:
O'Byrne, Paul. Patient Information. Accessed May 5, 2009. Exercise Induced Asthma
Storms WW. Accessed May 22, 2009. Asthma Associated With Exercise. Immunol Allergy Clin North Am. 2005 Feb;25(1):31-43.
