Like the name suggests, exercise induced asthma or exercise induced bronchospasm (EIB) is asthma that is triggered by vigorous or prolonged exercise or physical exertion. Most people with chronic asthma experience symptoms with exercise; however there are some people without asthma who can experience symptoms only with exercise.
Symptoms usually start within 5-20 minutes of starting exercise or can start 5-10 minutes after completing exercise and include:
• Chest tightness
• Shortness of breath
• Excessive fatigue with exercise
Mechanism/ Pathophysiology of EIB
There may be more than one biological mechanism that causes EIB. A change in the temperature and moisture content of inhaled air is the primary change that causes symptoms in these individuals.
During normal breathing, we inhale air through the nose which is first warmed and moistened through the nasal passages. During strenuous exercise, we breathe through the mouth and the air tends to be cooler and drier; strenuous exercise sets in motion molecular events that trigger inflammatory changes which cause narrowing of the airways and mucous production.
EIB can also be made worse when the patient is sick with a cold or when the allergens ( pollen, mold) counts are really high during the allergy seasons or when the person exercises in very cold weather.
Exercise induced asthma is diagnosed on the basis of a reliable history and supportive tests like Spirometry and sometimes an Exercise challenge test.
A Spirometry is a breathing test that is done in the office to measure a patients lung capacity at baseline and to see the effect of a bronchodilator on lung function.
An Exercise challenge test is sometimes necessary in patients who have exercise induced symptoms but don't seem to be getting better with treatment. Such patients may have other conditions which mimic EIB and may need to be treated differently.
An Exercise Challenge test is usually done in our office using a treadmill - the patient is made to undergo vigorous exercise in order to provoke the patients symptoms; Spirometry is done pre -exercise and again post exercise every few minutes to determine if the patient is showing evidence of bronchospasm.
Conditions that can mimic exercise induced asthma include:
• Vocal cord dysfunction
• Gastroesophageal reflux disease
• Other lung disorders
• Cardiac arrhythmia or other conditions
Should exercise be avoided by patients who have EIB?
No, asthma should not be used as an excuse to avoid exercise. Exercise induced symptoms can be both prevented and treated with medications as well as taking certain precautionary measures during exercise.
Short acting Beta2 agonists (SABA's) like albuterol help to relieve bronchial spasm and are the most commonly prescribed inhalers for EIB -the inhaler is usually taken 10 minutes before exercise as a preventive measure and can be used additionally if a patient experiences symptoms. However, if pre-exercise treatment alone is not enough and the patient needs this inhaler regularly even after exercise, then he/ she may need a daily controller medication.
Daily controller medications:
For those patients with chronic asthma and those requiring SABA's daily for EIB ,there are other inhalers ( such as inhaled corticosteroids and LABA's ) and leukotriene modifiers (Singulair) which are often prescribed as controller medications. These medications help to control inflammation and can also help to prevent exercise induced symptoms.
In addition, the patient may want to take certain extra precautions like trying to avoid exercising outdoors in very cold weather and using a face mask if exercising during high pollen count days which would also help to minimize symptoms. A gradual warm up routine prior to vigorous exercise and a cooling down routine post exercise also helps.
Certain exercises like swimming are better tolerated by these individuals because it is usually done in a warm moist air environment.
Activities that involve short intermittent periods of exertion like volleyball, walking and wresting are generally better tolerated than other strenuous exercises like soccer, ice hockey and basketball but most patients with exercise induced asthma should be able to actively participate in sports and activities.
The board certified and eligible physicians at Allergy Partners offer extensive training, knowledge and experience in diagnosing and treating patients with exercise induced asthma. As the leaders in allergy and asthma care, our physicians take a detailed history, perform careful physical examination and create a patient centered treatment plan to ensure all needs are addressed thoroughly.
Mona Hirani, MD
Allergy Partners of Chicago