Exercise or other physical activity can trigger asthma-related symptoms. Symptoms usually occur during or right after physical activity. However, if asthma is under control, exercise should not cause problems. In fact, asthmatic people can enjoy any physical activity without developing symptoms, if they follow a few ground rules.
Exercise-induced bronchoconstriction (EIB) is airflow obstruction caused by physical activity in normal people. Almost 90% of asthmatic patients will experience EIB symptoms during exercise. EIB is a very common asthma symptom in teenagers and young adults.
Symptoms of EIB
Major symptoms of EIB include:
- Chest tightness
- Shortness of breath
Coughing is the most prevalent EIB symptom and often the only symptom. Symptoms usually develop shortly after physical activity has begun and get worse even after stopping the activity. Symptoms usually range from mild to severe and mostly subside within 30 minutes.
Causes of EIB
During exercise, breathing is deeper and faster because of higher oxygen demands of the body. People tend to breathe through their mouth when they are active and, as a result, the air inhaled is colder and drier compared to the air taken in through the nose. Dry or cold air is the main cause of airway narrowing or bronchoconstriction. Physical activity that exposes people to cold and dry air can be a trigger for asthma symptoms. Other common triggers of EIB are polluted air, high pollen counts, smoke, fumes or exposure to other irritants.
Diagnosis of EIB
Physicians normally diagnose EIB using a series of analysis and tests.
The patient’s health history is first analyzed using previous reports and a series of questions. This is followed by a breathing test at rest using a device called spirometer. If the breathing test gives abnormal results, the doctor might repeat the test after inhalation of drugs such as albuterol. If there is improvement in the breathing test after inhaling the drug, then the diagnosis is most likely asthma.
If the breathing test is normal, an exercise challenge or a bronchoprovocation test is administered. The patient is made to run on a treadmill or cycle for a certain time period, before and after which breathing tests are conducted using a spirometer. If the results post exercise are poor, then EIB may be the case.
Treatment of EIB
Physicians develop a comprehensive treatment plan based on the severity of asthmatic signs and symptoms. Controller medications such as inhaled steroids, mast cell stabilizers, and leukotriene modifiers are used to treat EIB associated with asthma. Short-acting beta-agonists such as albuterol are also used before exercise to control the symptoms of EIB. Apart from medications, cool-downs and warm-ups may prevent or reduce symptoms of EIB. Exercise should be minimal at low temperatures, high levels of pollution or if the individual has a viral infection.
People with EIB should avoid sports or workouts in cold or dry weather such as ice hockey, ice skating, skiing, and snowboarding. Sports that require a lot of stamina such as soccer or long distance running could be too stressful for people with EIB. Some sports require only short bursts of activity and hence are least likely to trigger EIB. Examples of such sports and activities are volleyball, gymnastics, baseball, hiking, walking, and swimming in a humid environment.
Children with EIB need special care and their teachers and coaches need to be informed of their condition. They may need medication to contain any symptoms before an activity.
However, regular physical activity is recommended for everyone, including asthmatic people. Short-acting beta 2-agonists inhaled 15 minutes before exercise should be very helpful in preventing and controlling EIB associated with asthma.
Reviewed by Yolanda Smith, BPharm