Understanding Exercise-Induced Asthma
With contributions from Krystina O.
You feel like you’re a bit “extra” winded during your daily run these days. You’ve always thought you’re in good shape – yet you’re huffing and puffing when you walk up a flight or two of stairs. Even a power walk has you wheezing these days.
What Is Exercise-Induced Asthma?
According to the Asthma and Allergy Foundation of America (AAFA), “Airflow obstruction that occurs because of exercise is exercise-induced bronchoconstriction.” Exercise-induced bronchoconstriction (EIB) is better known is exercise-induced asthma, which is actually an older term for this phenomenon.
EIB is a more accurate term for exercise-induced asthma as it more accurately depicts what is happening in the body – this phenomenon is not causing asthma to occur.
The AAFA states that upwards of 90 percent of all people with asthma have symptoms of exercise-induced asthma.
What Causes Exercise-Induced Asthma?
There is current research that is being performed to explore the exact cause of exercise-induced asthma. According to Mayo Clinic, “strenuous exercise sets in motion molecular events that result in inflammation and the production of mucus in the airways.” However, researchers also believe that there may be more than one biological process at play.
Exercise-induced asthma can also be caused by other means, aside from asthma! Other factors that may trigger this type of bronchoconstriction include:
- Respiratory infections.
- Cold air.
- Dry air.
- Chlorine that is used in swimming pools.
- Air pollution.
- High pollen counts.
- Certain chemicals, such as the chemicals used to resurface ice rinks.
Exercise-Induced Asthma Symptoms
Symptoms of exercise-induced asthma are similar to that of asthma – except they typically occur just during exertion.
The most common symptom of exercise-induced asthma is coughing. For that reason, it can go undiagnosed. Other exercise-induced asthma symptoms may include:
- Shortness of breath.
- Chest tightness.
According to AAFA, symptoms do not typically present itself right away.
For example, if you’ve begun your daily run and you are feeling pretty good, your symptoms likely will present themselves during your run and will worsen five to ten minutes after you’re done exercising.
You may even experience a “late-phase” of symptoms – symptoms that are experienced anywhere from four to 12 hours after exercise is ceased. Late-phase symptoms are typically less severe.
Do I Have Exercise-Induced Asthma?
In relatively good shape but you’ve been huffing and puffing? How do you know that you’ve got exercise-induced asthma?
Well, first it takes an appointment with your physician.
Your physician will likely perform a physical exam and ask you questions about your symptoms. He or she will probably order several medical tests to rule out other medical conditions.
One test that will likely be ordered? Spirometry. Spirometry measures how well your lungs function during exercise. Specifically, it measures how much air you inhale, exhale, and how quickly you can exhale. After, a bronchodilator is administered, and the test is repeated, and the results are compared. This test is important because it can diagnose asthma versus exercise-induced asthma.
An exercise challenge test can also be performed. This test utilizes a treadmill to illicit symptoms by allowing the participant to exercise until breathing is increased. Spirometry is performed before and after.
As an alternative to an exercise test, occasionally the following tests may be utilized. If symptoms are produced, it is thought that the “test should produce virtually the same lung function you have when exercising.” For these tests, spirometry is utilized before and after to detect changes in lung function.
- Methacholine challenge: an inhaled agent causes bronchoconstriction of the lungs.
- Eucapnic voluntary hyperventilation (EHV) challenge: inhaling a combination of several gases (dry air that is composed of nitrogen, carbon dioxide, and oxygen) that “simulates the exchange of air when breathing is difficult.”
- Mannitol challenge: inhaling a dry powder that involves losing water on the surface of the lungs. This causes bronchoconstriction in people who have sensitive airways.