Exercise-Induced Asthma

Asthma is a chronic inflammation of the breathing passages (airways) of the lungs. Asthma is characterized by episodic attacks or periods of respiratory symptoms that can vary in intensity, separated by periods of mild symptoms, or no symptoms at all. The inflammatory reaction of asthma can be triggered by external factors or specific situations or exposures. When a person with asthma is exposed to one of his or her triggers, the inflammation worsens and symptoms begin.

• The list of possible triggers of asthma is lengthy and varied.
• Each individual with asthma has his or her own specific trigger or set of triggers, not always easily identifiable.
• These triggers generally are related to the way we breathe or the condition of the atmosphere we breathe in.
• Triggers include contaminants in the air, such as smoke, pollution, vapors, dust, or other particles; respiratory infections, such as colds and flu (viruses); allergens in the air, such as molds, animal dander, and pollen; extremes of temperature or humidity; and emotional stress.

Exercise is a common trigger of asthma attacks.

• Exercise can even induce an asthma attack in people who have no other triggers and do not experience asthma under any other circumstances.
• People with exercise-induced asthma are believed to be more sensitive to changes in the temperature and humidity of the air.
• When you are at rest, you breathe through your nose, which serves to warm, humidify, and cleanse the air you inhale to make it more like the air in the lungs.
• When you are exercising, you breathe faster, leaving less time for the air to become conditioned for the lungs, thus the air that hits your lungs is colder and drier. The contrast between the warm air in the lungs and the cold inhaled air or the dry inhaled air and moist air in the lungs can trigger an attack.

Once the attack is triggered, the airways spasm, resulting in irritation. This irritation leads to inflammation, and a change in the lining of the airways of the lung. This becomes more glandular and secretes mucus, along with thickening of the airway wall. These all combine to narrow the airways, increasing resistance, making it more difficult for air to move in and out of the lungs. This effect is more dramatic on exhalation because this is the time in the respiratory cycle when the chest cavity has a positive pressure outside of the airways. When inhaling the pressure in the chest cavity is negative and there is more of a vacuum, helping to suck the airways open.

• The swelling and extra mucus partially block or obstruct the airways. This makes it more difficult to push air out of your lungs (exhale).
• When asthma is left untreated and the inflammation persists, permanent narrowing of the airways can occur. If this happens, this chronic asthma can also be referred to as chronic obstructive pulmonary disease (COPD). For some forms of asthma, it is important that chronic maintenance medication are used to prevent the development of COPD. Asthma cannot be cured, but it can be controlled by medication. Fortunately, in those with only exercise-induced asthma (EIA), maintenance therapy is often not required and medication can simply be taken before exercise.
• With appropriate treatment, almost everyone with EIA can enjoy the mental and physical benefits of regular exercise.
• The large number of elite athletes who have asthma attests to the effectiveness of asthma medication.
• Whether you walk around your neighborhood or run marathons, asthma doesn't need to stop you from reaching your exercise goals.

Asthma has two components: the underlying chronic inflammation and the periodic attacks. We do not know for certain what causes the underlying inflammation. What we do know is that the tendency to have asthma runs in families and that some people are born with the tendency to have asthma.

We do know that exposure to a trigger causes asthma attacks. In exercise-induced asthma, that trigger is rapid movement of air into the lungs before it is warmed and humidified. This often occurs because of an increased respiratory rate with exercise. The attack is similar in many ways to an allergic reaction.

• An allergic reaction is a response by the body's immune system to an "invader." That invader can be a substance or anything that the body senses as "different."
• When the cells of the immune system sense an invader, they set off a series of reactions that help fight off the invader.
• It is this series of reactions that causes the inflammation that leads to the production of mucus and bronchospasm. These responses cause the symptoms of an asthma attack.
• The spasm of the airways is in response to some stimulus causing this asthma reaction (reactive airways disease).

Sports and games that require continuous activity or are played in cold weather are most likely to trigger an asthma attack.

• Long-distance running
• Basketball
• Soccer
• Hockey (ice and field)
• Cross-country skiing

Sports that are less likely to trigger an asthma attack are those that require short bursts of activity interspersed with breaks.

• Walking
• Recreational biking (not racing)
• Hiking
• Swimming
• Short-distance running and track/field events
• Baseball or softball
• Golfing
• Football
• Volleyball
• Wrestling
• Gymnastics
• Downhill skiing

Symptoms usually begin about five to 20 minutes after beginning to exercise. The symptoms often peak about five to 10 minutes after stopping exercise then gradually diminish. The symptoms are typically gone within an hour, but they may last longer. Symptoms include one or a combination of the following:

• Coughing
• Wheezing
• Chest tightness
• Chest pain
• Prolonged shortness of breath
• Extreme fatigue
• Decreased exercise capacity

Symptoms of asthma may be more subtle in children.

• Children may complain of not being able to keep up with peers in games and sports.
• They may say they don't like games or avoid participating.
• This can lead to problems with socialization or self-esteem in some children.

If you think you or your child may have exercise-induced asthma, promptly make an appointment with your health-care professional.

If you or your child has exercise-induced asthma, you should have an action plan worked out in advance with your health-care professional. This plan should include instructions on how to prevent an attack while exercising, what to do when an asthma attack occurs, when to call the health-care professional, and when to go to a hospital emergency department.

The following is an example of an action plan in case of an exercise-induced attack:

• Take two puffs of an inhaled beta2-agonist (a rescue medication) with one minute between puffs. If there is no relief, take an additional puff every five minutes. If there is no response after eight puffs, which is 40 minutes, your health-care professional should be called.
• Your health-care professional should also be called if you have an asthma attack when you are already taking oral or inhaled steroids or if your inhaler treatments are not lasting four hours.
• Keep in mind that these are general guidelines only. If your health-care professional recommends another plan for you, follow that plan.

Although asthma is a reversible disease, and treatments are available, people can die from a severe asthma attack.

• If you are having an asthma attack and have severe shortness of breath or are unable to reach your health-care professional in a short period of time, you must go to the nearest hospital emergency department.
• Do not drive yourself to the hospital. Have a friend or family member drive. If you are alone, immediately call 911 for emergency medical transport.

If you are having an asthma attack, your health-care professional (whether your primary-care provider or an emergency-department physician) will ask you questions about your symptoms, medical history, and medications. Answer as completely as you can. He or she will also examine you and observe you as you breathe.

He or she will assess the severity of the attack. Attacks are usually classified as mild, moderately severe, or severe. This assessment is based on several factors.

• Symptom severity and duration
• Degree of airway obstruction
• Extent to which the attack is interfering with regular activities

If you have had symptoms and are seeking medical care afterward, the health-care professional will ask questions and perform tests to search for and rule out or exclude other causes of the symptoms. The evaluation will almost certainly include tests of how well you can breathe at rest and may include tests during exertion. These tests are done at rest, after six to eight minutes of exercise, and then at regular intervals until at least 30 minutes after you have stopped exercising. Proper diagnosis is essential to ensure that the most appropriate treatment is given.

Measurements of how well you are breathing can be assessed using the following methods:

• Spirometry: The spirometer is a device that measures how much air you can exhale and how forcefully you can breathe out. The test may be done before and after you inhale a medication. Spirometry is a good way to see how much your breathing is impaired during an attack. This test must be done in the medical office; you may exercise on a treadmill or stationary bicycle. Normally, individuals can blow 70% of their lung capacity out of their lungs in one second. This is referred to as the forced expired volume in one second (FEV1). If airflow is obstructed, this number will be less than 70%. Often lung function in patients with exercise induced asthma is normal.
• Peak flow meter: This is another way of measuring how forcefully you can breathe out during an attack. This device is small and portable and can be used "in the field." This allows testing after six to eight minutes of your usual activity.
• Oximetry: A painless probe, called a pulse oximeter, may be placed on your fingertip to measure the amount of oxygen in your bloodstream.
• Other tests can be used to determine if airways have a tendency to be reactive. These include exhaled nitric oxide measurement and an airway challenge test with methacholine. The methacholine challenge can result in significant asthma symptoms and therefore is done in a facility with the capability of handling potential complications.

No blood test can pinpoint the cause of asthma.

• Your blood may be checked for signs of an infection that might be contributing to the symptoms.
• In severe attacks, it may be necessary to sample blood from an artery to determine exactly how much oxygen and carbon dioxide are present in your bloodstream.

A chest X-ray may also be taken. This is mostly to rule out other conditions that can cause similar symptoms.

In many instances, the history is the most important clue to the diagnosis of exercise-induced asthma. Oftentimes, armed with this information, the health-care professional will empirically trial a medication for exercise-induced asthma. Follow-up visits will then determine if this medication was effective in reducing the symptoms associated with exercise.

Since exercise-induced asthma is a chronic disease, treatment goes on for a very long time. Some people have to use medication for the rest of their lives. The best way to improve your condition and live your life on your terms is to learn all you can about your asthma and what you can do to make it better.

• Become a partner with your health-care professional and his or her support staff. Use the resources they can offer information, education, and expertise to help yourself.
• Follow the treatment recommendations of your health-care professional. Understand your treatment. Know what each drug does and how it is used.
• Visit your health-care professional as scheduled.
• Promptly report any changes or worsening of your symptoms.
• Report any side effects you are having with your medications.

The goals of treatment are as follows:

• To prevent attacks
• To carry on with normal activities
• To maintain normal or near-normal lung function
• To have as few side effects of medication as possible

Work with your health-care professional to develop an action plan. Follow your treatment plan closely to avoid an asthma attack during and after exercising. If you do have an asthma attack, the action plan will help you control the attack and make the decision about when to seek medical care.

If you should have an asthma attack, move to the next step of your action plan. Keep the following tips in mind:

• Take only the medications your health-care professional has prescribed for your asthma. Take them as directed.
• If the medication is not working, do not take more than you have been directed to take. Overusing asthma medications can be dangerous.
• Do not take cough medicine. These medicines do not help asthma and may cause unwanted side effects.
• Aspirin and nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin), can cause asthma to worsen in certain individuals. These medications should not be taken without the advice of your health-care professional.
• Do not use nonprescription inhalers. These contain a very short-acting inhaler that may not last long enough to relieve an asthma attack and may cause unwanted side effects.
• Do not take any nonprescription preparations, herbs, or supplements even if they are completely "natural," without talking to your health-care professional first. Some of these may have unwanted side effects or interfere with your medications.
• Be prepared to go on to the next step of your action plan if necessary.

If you think your medication is not working, let your health-care professional know immediately.

Most people with exercise-induced asthma, if exercise is their only trigger, do not have to take medication every day (unless they exercise every day). Medication is taken before exercising, each time you exercise, to prevent an attack.

• The medications most widely used by people with exercise-induced asthma are the short-acting beta2-agonist bronchodilator inhalers.
• Inhaled corticosteroids, even used intermittently, can effectively control the symptoms of EIA.
• Other preventive medications are inhaled cromolyn sodium, such as Intal, and oral leukotriene inhibitors, such as montelukast (Singulair).

Precautions that may help reduce your chance of having an asthma attack include the following:

• Spending time warming up before starting strenuous exertion can help prevent asthma symptoms. Similarly, a gradual cooling down after exertion can prevent symptoms after exertion.
• Avoid exertion when you have a respiratory tract infection, such as a cold, flu, or bronchitis.
• Avoid exertion in extremely cold weather.
• If you smoke, quit.
• If you have allergies, avoid exertion when a reaction is likely to be triggered, as when the pollen count is high or the pollution index is high.

If you have frequent exercise-induced asthma attacks despite using preventive medication, or if you have attacks when you are not exercising, you need to see your health-care professional right away. You may need to use daily medication to control the underlying inflammation that is causing your frequent attacks.

Together, you and your health-care professional will develop an action plan for your particular situation in case of asthma attack. The action plan will include the following:

• How to use rescue medication
• What to do if the rescue medication does not work right away
• When to call the health-care professional
• When to go directly to a hospital emergency department

Inhaled, short-acting beta2-agonist bronchodilators are the medications most often used to prevent asthma attacks in exercise-induced asthma.

• Use two to four puffs five to 30 minutes before exercising. The medication works best if taken just before exercising.
• This class of drugs is chemically related to adrenaline, a hormone produced by the adrenal glands.
• Inhaled beta2-agonists work rapidly (within minutes) to open the breathing passages. They relax the muscles of the breathing passages, dilating the passages and decreasing the resistance to exhaled airflow, making it easier to breathe.
• They are effective in most people with exercise-induced asthma.
• The effects last as long as four to six hours.
• They have no effect on the underlying cause of the asthma attack.
• They can also be used to relieve symptoms if an attack occurs.
• Side effects include rapid heartbeat and shakiness.
• Albuterol (Proventil, Ventolin) is the most frequently used beta2-agonist medication.

Longer-acting (12-hour) beta2-agonist inhalers, including salmeterol (Serevent) and formoterol (Foradil), are also available. These are not used alone for asthma. They should only be taken in combination of inhaled corticosteroids. Usually this treatment is reserved for asthma patients with more significant disease burden than exercise-induced asthma.

Inhaled corticosteroids such as beclomethasone (Qvar), fluticasone (Flovent), and mometasone (Asmanex) are also effective therapy for exercise-induced asthma. For effect, these work better if taken a few hours before exercise.

Asthma is a long-term disease, but it can be managed. Your active involvement in treating this disease is vitally important.

• Take your prescribed medication(s) as directed.
• If you smoke, quit.
• See your health-care professional regularly according to the recommended schedule.
• By following these steps, you can help minimize the frequency and severity of your asthma attacks.

Treatment in exercise-induced asthma is focused on preventing or minimizing asthma attacks. If you take your prescribed medication as directed, you should be able to exercise without asthma symptoms.

Most people with exercise-induced asthma are able to control their condition if they work together with a health-care professional and follow their treatment regimen carefully.

People who do not seek medical care or do not follow an appropriate treatment plan are likely to experience worsening of their asthma and deterioration in their ability to function normally.