Exercised-induced asthma (EIA) also called exercise-induced bronchoconstriction (EIB) is a narrowing of the airways in the lungs that is triggered by physical activity. EIA/EIB causes a person to experience breathing difficulties after strenuous exertion. In both adults and children, the symptoms of this condition include:
They usually appear within 8 to 12 minutes after exercise begins, reaching a peak five to ten minutes after exercising. In children, EIA/EIB symptoms often appear as coughing during or after exercising and/or as abdominal pain during exercise. Most people recover from EIA/EIB within one hour, however some experience a second attack 3 to 9 hours after exercise.
This condition occurs in people whose airways are acutely sensitive to sudden changes in temperature and humidity. During strenuous exercise, people usually breathe through their mouth rather than their nose; this allows cold dry air to reach the lower airway and lungs. In addition to mouth-breathing, such things as air pollution, high levels of pollen, and respiratory infections are also factors in EIA/EIB.
Studies have shown that 80% of all asthmatics will experience EIA/EIB symptoms during or after exercise, while 40% of all people with nasal allergies may experience asthma symptoms during exercise.
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 you 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 EIA/EIB.
Although EIA/EIB is more prevalent among Olympic athletes than among the general population, this condition is not limited to athletes. School-age children who participate in physical education classes and play sports are also susceptible. Even those who engage in non-athletic, but strenuous activities (for example, yard work and shoveling snow) may experience breathing difficulties after a period of exertion. In both children and adults, the more subtle symptoms of EIA/EIB are often missed when people mistakenly blame reluctance to participate in sports or poor athletic performance as being out of shape.
A diagnosis of EIA/EIB does not mean a person must give up all strenuous physical activity. An allergist can prescribe inhaled and/or oral medications that, taken before exercising, will help control and prevent EIA/EIB. In addition, the doctor will explain to the patient (and, if necessary, to teachers and coaches) how a combination of proper training and medication can alleviate the symptoms of this condition. With appropriate diagnosis and treatment, a person with EIA/EIB can continue to reap the benefits of physical exercise and even excel in sports.
If you have been diagnosed with EIA/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 EIA/EIB symptoms in 80 to 90% of patients.