Exercise induced asthma (EIA) is asthma which is triggered by vigorous or prolonged physical activity. Most people with chronic asthma will experience symptoms with exercise. However, there are numerous people without chronic asthma who develop symptoms only during exertion.
During normal breathing, the air we breathe is first warmed and moistened by the nasal passages. During exercise, people tend to breathe through the mouth, resulting in colder and drier air that is inhaled. In exercise-induced asthma, the muscle bands around the airways are sensitive to these changes in temperature and humidity of the inhaled air and react by contracting (or spasming) which narrows the airway. This results in symptoms of asthma which include:
- Tightness in the chest
- Unusual fatigue while exercising
- Feeling short of breath while exercising
Other factors that can influence the degree of symptoms with exercise are the presence of pollens and pollutants in the air, as well as upper respiratory infections.
The symptoms of exercise-induced asthma generally begin within five to 20 minutes after the start of physical activity, or 5-10 minutes after brief exercise as stopped.
If you are experiencing any of these symptoms with physical exertion, inform your physician.
Exercise should not be avoided because of exercise-induced asthma. There are steps that can be taken to control the symptoms to allow you or your child to maintain normal physical activity.
Inhaled medications taken prior to exercise can control and prevent exercise induced asthma symptoms. The preferred medications are the short acting beta <sub>2</sub> agonist inhalers (albuterol, pirbuterol) which taken 15-20 minutes before exercise can prevent the airways from spasming. These medications can provide control of EIA for as long as 4 to 6 hours. Other medications that may be useful are the long acting bronchodilators that provide 12-hour control (salmeterol, formoterol). When taken before work or school, EIA symptoms may be avoided with any physical activity throughout the day. It is important however to always have a short acting bronchodilator available in case symptoms still occur. If these measures fail to control EIA symptoms, your physician may determine that daily therapy is needed to control the underlying inflammatory process that results in unstable airways.
In addition to medications, a warm-up phase prior to exertion and a cool-down period after can help prevent EIA. Exercise should be limited during high pollen days (if allergic) or when temperatures are extremely low and air pollution levels are high. The presence of viral upper respiratory infections can also increase symptoms and exercise should be restricted when present.
For people with exercise-induced asthma, some activities are better tolerated than others. Activities that involve short, intermittent periods of exertion such as volleyball, gymnastics, baseball, walking, and wrestling are generally well tolerated. Activities that involve long periods of exertion (soccer, distance running, basketball, and field hockey) may be less well tolerated as well as cold weather sports (ice hockey, cross-country skiing, ice skating). However, many people with asthma are able to fully participate in these activities. Swimming, which is a strong endurance sport, is generally well tolerated by asthmatics because it is usually performed in a warm, moist air environment. It is also an excellent activity for maintaining physical fitness.
Maintaining an active lifestyle is important for both physical and mental health. The goal of treating exercise-induced asthma is to allow full participation in sports and activities. Communication with your or your child's health care provider when the treatment plan is not effective to control EIA is important. Appropriate treatment will allow for maximum benefits from your or your child's exercise program.