ACSM'S Health & Fitness Journal:
DEPARTMENTS: Fitness Focus Copy-and-Share
This copy-and-share column discusses exercise-induced asthma.
Dixie L. Thompson, Ph.D., FACSM, is the director of the Center for Physical Activity and Health and professor and head of the Department of Exercise, Sport, and Leisure Studies at the University of Tennessee, Knoxville.
Asthma is a term used to describe conditions in which breathing becomes difficult as a result of exposure to an irritant. Allergic asthma is common and can be caused by factors such as pet dander or pollen. In some, asthma symptoms can result from exercise. Exercise-induced asthma (EIA) can be viewed as a deterrent to exercise, but with proper medical oversight, most people with EIA can engage in exercise without major problems.
CAUSES AND SYMPTOMS
The exact cause of EIA is unclear and may differ among individuals. Two commonly described triggers for EIA attacks are cold and/or dry air. Under normal circumstances, air is warmed and moistened by the time it reaches the lungs. Because exercise increases breathing rate, the body's ability to warm and saturate the air with moisture may be compromised. Other factors that may increase EIA attacks are high levels of pollen, pollution, and chemicals such as paint fumes. People also are more likely to have an EIA attack if they have a cold or respiratory infection.
Regardless of the source of the irritation, EIA symptoms are the result of an inflammatory response characterized by a narrowing of the lungs' airways and an increase in mucus secretion. These changes make breathing more difficult. Symptoms often occur 5 to 15 minutes after starting exercise but also can begin after exercise is over. Common symptoms of EIA are:
* shortness of breath
* tightness in the chest
* coughing and/or wheezing
* fatigue and/or poor performance
IMPORTANCE OF MEDICAL OVERSIGHT
It is estimated that 12% to 15% of individuals have EIA. People with other asthmas have an increased chance of having EIA compared with people without allergies. The EIA episodes can range from mild to life threatening. Therefore, it is critically important that each individual consult his or her physician regarding any asthmatic condition including EIA.
To diagnose EIA, a physician will need to know a person's exercise history including situations that induce EIA and resulting symptoms. The physician may perform lung tests before and after exercise to document changes in lung function. Other tests such as chest radiography may be used to help clarify the diagnosis.
Fortunately, there are a number of prescription medications that can alleviate asthma. It is critically important that the patient communicate with his or her physician to understand dosing instructions and how to use any medication properly when exercising. People also should understand what symptoms should be reasons to seek emergency help.
MAKING EXERCISE CHOICES
Individuals should try to avoid exercising in situations that commonly trigger EIA. Avoiding exercise in really cold conditions is recommended. When exercising in the cold, wearing a mask or scarf over the nose and mouth can be helpful. One should not exercise in environments with high levels of irritants (smoke, pollution, pollen). People prone to bouts of EIA should avoid exercise when they have respiratory infections. Other recommendations include:
* use of warm-up and cooldown periods of 10 to 15 minutes
* progress slowly when beginning to train
* substitute moderate for vigorous exercise when needed
* breathe through the nose as much as possible during exercise
With proper medical oversight, most people with EIA can safely engage in exercise.
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