Health A-Z

What is exercise-induced asthma?

Exercise-induced asthma, or exercise-induced bronchoconstriction (EIB), happens when airways get smaller during exercise. Asthma triggered by sports or exercising can make it hard for you to breathe. You may have asthma symptoms like coughing, wheezing and shortness of breath during or after physical activity.

Asthma symptoms appear when the airways constrict (become narrower) during exercise. Symptoms are worse when the air is cold and dry, or when pollution levels and pollen counts are high.

People with exercise-induced asthma should warm up before exercising. Inhalers and other medications can prevent an EIB episode and open the airways.

What are the symptoms of exercise-induced asthma?

Symptoms can range from mild to severe. They can appear a few minutes after you start exercising or after you finish a workout. Symptoms usually start to improve after about 30 minutes of rest.

Sometimes, exercise-induced asthma can return up to 12 hours after you’ve finished exercising. They can appear even when you’re at rest. These are called “late-phase” symptoms. It may take up to a day for late-phase symptoms to go away.

Symptoms of asthma triggered by exercising include:

• Coughing after running or exercising. (Coughing is the only symptom for some people.)
• Wheezing.
• Difficulty breathing (shortness of breath). You may feel like it’s hard to push air out of your lungs.
• Tight feeling in the chest.
• Severe fatigue.

What causes exercise-induced asthma?

Rigorous physical activity and cold, dry air can trigger exercise-induced asthma. When you’re resting, you usually breathe through your nose. Your nose warms and moisturizes the air you breathe as it travels through your nostrils.

When you exercise, you breathe in through your mouth more often, and the air coming in remains cold and dry. If you have asthma, the bands of muscle around your airways react to the cold, dry air by constricting (becoming narrow).

Exercise-induced asthma is worse when:

• Air is cold and dry.
• Pollen counts are high.
• Pollution levels are high, causing poor air quality.
• You’re recovering from a cold or respiratory illness.
• You’ve breathed in smoke, chemicals or fumes from paint or cleaning supplies.

What sports commonly cause asthma symptoms?

If you have sports-induced asthma, you may want to choose certain activities over others. Endurance sports and activities that take place in colder temperatures are more likely to trigger symptoms. That’s because cold, dry air can constrict the airways and trigger symptoms of asthma.

Sports that are most likely to trigger symptoms of asthma:

• Require constant physical exertion: Long-distance running, soccer, basketball and other endurance sports require you to breathe heavily and constantly with little rest.
• Take place in colder weather: Skiing, ice hockey, ice skating and snowboarding commonly cause symptoms due to colder air temperatures.

Which activities are less likely to cause sports-induced asthma symptoms?

Indoor sports and those with short bursts of activity are less likely to trigger an asthma episode. But any activity can cause symptoms. Be sure to talk to your provider before starting any exercise program.

To avoid symptoms, you may want participate in sports or exercises that are best for asthma including:

• Activities with short bursts of energy: Asthma symptoms appear less often during sports that involve quick, short sprints with periods of rest. These sports include volleyball and baseball.
• Less-rigorous activities: Golf, biking and walking are often good choices for people with asthma.
• Indoor sports: Some indoor activities (like gymnastics) are less likely to trigger sports-induced asthma symptoms.
• Warm or humid environment: Swimming, diving and water polo have a lower risk of triggering sports-induced asthma symptoms. Moist pool air makes an EIB episode less likely. But some people find chlorine in a pool to be irritating. A saltwater pool can be a better choice, if you have one available.

How do I manage exercise-induced asthma?

There is no cure for asthma triggered by exercising or sports. Treatment focuses on preventing and relieving symptoms.

To avoid an episode, you should warm up for at least six minutes before starting exercise. Ask your provider to recommend the best warmup routine for your age and fitness level.

Your provider may recommend one medication or a combination of several medications. Some drugs open your airways while you’re experiencing exercise-induced asthma. Other medications prevent an episode. These medications include:

• Short-acting beta-agonist (SABA): These medications can relieve symptoms during an EIB episode. SABAs are a type of bronchodilator. They’re sometimes called rescue inhalers because you inhale (breathe in) the medicine, and it goes directly into your airways. SABAs can also prevent asthma symptoms if you take the medication about 15 minutes before exercise.
• Long-acting beta-agonist (LABA): Like SABA drugs, these medications let air flow by relaxing muscles in the airways. LABAs can prevent an EIB episode if you inhale the medication about 30 minutes to an hour before you exercise. But they aren’t effective as rescue inhalers. They won’t reverse symptoms once they’ve started.
• Inhaled corticosteroids: These drugs reduce swelling in the airways to increase airflow.
• Leukotriene modifiers: You take this medication by mouth to prevent the airways from becoming inflamed. Talk to your provider about the side effects of these drugs. Some people experience behavior changes and mood swings.
• Mast cell stabilizers: Taking this medication about 15 minutes before exercise can prevent symptoms. You inhale this medication through a nebulizer, a machine that turns liquid medicine into tiny droplets that you breathe in.

How do healthcare providers diagnose exercise-induced asthma?

Your provider will ask about your symptoms, including when you have them and how long they last. After listening to your lungs, your provider will ask you to perform an activity that usually triggers your symptoms (such as running outside). Then your provider will measure your lung function with a spirometry test.

During spirometry, you exhale as much air as you can as fast as possible. You breathe into a tube attached to a machine called a spirometer. The machine measures how well your lungs work after exercise.