Asthma and Exercise

Anyone exercising hard enough may have shortness of breath. But when this happens sooner than expected, or happens along with other symptoms such as chest tightness, wheezing, or cough, then it may be asthma.

Exercise is a common trigger of asthma. The terms "exercise asthma" or "exercise induced asthma" are often used, but these are some common ways that exercise makes asthma worse:

• Exercise sometimes making asthma symptoms worse in someone who does not usually need asthma medications (Intermittent Asthma).
• Exercise making asthma symptoms worse in someone is regularly on asthma medications (Persistent Asthma).
• Exercise causing asthma symptoms only with exercise, and the person has no other asthma history or symptoms. This is called Exercise Induced Airway Narrowing and is different from traditional asthma.

No matter which way it happens, breathing may be even harder when the air is colder and drier. At rest, breathing through the nose warms and humidifies (moistens) the air taken in. During exercise, breathing faster through the mouth lets air that is colder and drier than usual into the lungs. The colder and drier air can trigger symptoms like coughing and wheezing.

Once the airways are triggered the airway lining may begin to swell (inflammation), smooth muscle bands around the airway can tighten (bronchospasm), and extra mucus can be made. The swelling, tightened muscle bands, and extra mucus can partially block the airways. This makes it harder to get air in and out of the lungs. The exact way this happens may be different in traditional asthma compared to Exercise Induced Airway Narrowing.

Activities like long-distance running, hockey, and cross-country skiing are more likely to trigger symptoms because they are held in cold temperatures or have the player working hard for longer amounts of time. Activities like walking and swimming are less likely to trigger symptoms because players use short bursts of action mixed with breaks, or are done in warmer and more humid places.

Diagnosis

There is no one easy test for exercise-related asthma. The health care provider will ask questions to find a pattern of breathing symptoms during exercise. A physical exam may show wheezing which may mean asthma, but the exam may be normal. It is helpful to use other tests, like:

• Spirometry – Breathing tests can be done by spirometry (in an office setting) or pulmonary function testing (in a hospital setting) to measure lung function and capacity. A baseline test is compared to a follow up test to look for improvement after a trial of medication. This can help find out if traditional asthma is present.
• An exercise test: A breathing test can be checked before and after exercise to see if there is breathing function is worse after exercise.
• A breathing test can be checked before and after inhaling a dry mixture of gases to see if breathing function is worse. This is known as an eucapnic voluntary hyperventilation test.

Some patients will choose a trial of asthma medications to see if symptoms get better instead of testing options.

Treatment

If traditional asthma is diagnosed, then the health care provider will decide if it is Intermittent Asthma or Persistent Asthma. If it is Persistent Asthma, then a regular Long-Term Control Medication should be used. This is usually an anti-inflammatory medication taken every day to prevent trouble. The patient will usually also have a Quick-Relief Medication. This is a short acting bronchodilator (typically albuterol) which can be used as needed for quick relief of symptoms.

If it is Exercise Induced Airway Narrowing, using medications before exercise can help. This is usually done by using a short-acting bronchodilator 15 minutes before exercise. There are other medication options if this does not work.

No matter how the symptoms happen, people with asthma should watch for warning signs of short term and long term trouble. Asthma is not under control if:

• Breathing symptoms happen more than twice a week
• A Quick-Relief Medication is needed more than twice a week for trouble (does not include medication used before exercise)
• Severe symptoms such as cannot walk or talk or sleep due to breathing trouble

Everyone with asthma needs to have an Asthma Action Plan. This lists warning signs, steps to take in case of symptoms getting worse, and when to call for help. People with asthma should work with their doctor to get their asthma under control and make an Asthma Action Plan that they can use.

Prevent Symptoms

There are things that can be done to help prevent symptoms with exercise. Start with a warm up period of light activity before any harder exercise. Avoid exercising in cold and dry air. Avoid exercise when other triggers, such as respiratory infections or smoke, can cause more trouble breathing.

The goal is to be able to exercise without symptoms. Most people with asthma can take part fully in sports or be as active as they would like to be. They need to work with their health care provider and follow their Asthma Action Plan to be able to do this.

Learn more about asthma triggers.

Adapted from the Guidelines for the Diagnosis and Management of Asthma, National Asthma Education and Prevention Program of the National Heart, Lung and Blood Institute, Expert Panel Report 3, 2007.