What is exercise-induced asthma?
Asthma is a lung condition that causes wheezing, coughing, shortness of breath, and chest tightness. Exercise-induced asthma is a form of asthma that some people have during or after physical activity. Exercise-induced asthma is common. People with chronic asthma can develop symptoms whenever they are exposed to a "trigger" of the asthma, such as a virus, pollen, dust, or cigarette smoke. About 80 to 90 percent of people who have chronic asthma have exercise-induced asthma.
And about 35 to 40 percent of people with seasonal allergies also have exercise-induced asthma and symptoms worsen during the spring and fall.
Exercise-induced asthma is initiated by the process of respiratory heat exchange (the fall in airway temperature during rapid breathing followed by rapid reheating with lowered ventilation). The more heat transferred, the cooler the airways become, the more rapidly they rewarm, and the more the bronchi are narrowed. During intensive exercise, the amount of air taken in compared with that at rest may increase by 30 times. This large volume of air must be heated and humidified as it travels to the lungs to deliver oxygen. It is believed that the stress of this demand on the airways triggers the asthmatic episode. This stress provokes certain inflammatory cells, which then release various substances leading to airway constriction (or bronchospasm), swelling, and mucous plugging of the airways. Not all exercises provoke an attack and the same exercise may not always produce the same symptoms. Exercising in cold and dry air is likely to cause an attack, whereas a warm humid environment (such as an indoor swimming pool) may be somewhat protective.
Running, jogging and vigorous sports that result in mouth-breathing are most likely to trigger an exercise-induced asthma attack - especially when done in cold, dry air. Breathing through the nose and/or wearing a protective scarf or mask can help keep inhaled air warm and moist. Warm-up and cool-down periods can help prevent the abrupt changes that can trigger symptoms. Cold-weather sports, such as ice hockey and skiing, are also likely to provoke an attack in susceptible people. That's because exercise-induced asthma usually stems from a loss of heat and moisture in tissues lining the respiratory tract as the result of inhaling large amounts of cold, dry air. Once the attack is triggered, the airways begin to swell (bronchospasm) and secrete large amounts of mucus. The swelling and extra mucus partially block or obstruct the airways. This makes it more difficult to push air out of your lungs (exhale). Because of this, asthma is referred to as a chronic obstructive pulmonary disease (COPD), like emphysema and chronic bronchitis.
Symptoms of exercise-induced asthma vary widely. Chest tightness, cough, slight shortness of breath, fatigue during exercise or asthma attacks with rapid, shallow breathing, difficulty breathing, wheezing, chest tightness, and coughing. Most people with asthma have symptoms when exercising, especially if the air is cold and dry. Others only show asthma symptoms when they exercise (exercise-induced asthma). Severe reactions are called exercise-induced bronchospasm or bronchospasm. Theories now show that EIA may be simply a mild form of chronic asthma.
Most attacks are brief, lasting only a few minutes, but some can continue for hours and may require medication. Symptoms of exercise-induced asthma typically include coughing, tightness in the chest or wheezing and shortness of breath.
The key to treating exercise-induced asthma is pre-treatment. Inhaled medications taken prior to exercise can control and prevent exercise-induced asthma symptoms. The preferred medications are short-acting beta 2-agonists such as albuterol. Taken 15-20 minutes before exercise, these medications can prevent the airways from contracting and control exercise-induced asthma for as long as 4-6 hours. By taking medication before exercise, the airway narrowing can be simply and effectively blocked. A variety of medications may be used in exercise-induced asthma. This is a situation where short-acting inhaled beta-agonists (normally called relief or rescue drugs) can be used effectively to prevent or control symptoms. They are usually given 10 to 15 minutes before exercise, and can last up to 4 hours.
In addition to taking medications, warming up prior to exercising and cooling down afterwards can help prevent an attack. For those with known allergies, exercise should be limited during high pollen days or when temperatures are extremely low and air pollution levels are high.
More information on asthma
What is asthma? - Asthma is a chronic inflammatory respiratory disease characterized by periodic attacks of wheezing, shortness of breath, and a tight feeling in the chest.
What types of asthma are there? - Types of asthma include child-onset asthma, adult-onset asthma, exercise-induced asthma, cough-variant asthma, occupational asthma, nocturnal asthma.
What's bronchial asthma? - Bronchial asthma is a disease of the lungs in which an obstructive ventilation disturbance of the respiratory passages evokes a feeling of shortness of breath.
What is exercise-induced asthma? - Exercise-induced asthma is a form of asthma that some people have during or after physical activity. Exercise-induced asthma is common.
What is adult-onset asthma? - Adult onset asthma generally is the onset of asthma for the first time in someone of middle age or older. Adult-onset asthma develops after age 20.
What is status asthmaticus? - Status asthmaticus is a severe asthma episode that does not respond to standard treatment. Status asthmaticus is caused by severe bronchospasm.
What causes asthma? - Asthma is caused by inhaling an allergen that sets off the chain of biochemical and tissue changes leading to airway inflammation, bronchoconstriction, and wheezing.
What're the asthma triggers? - Many risk factors have been linked to triggering asthma attacks. There are two basic types of asthma triggers, allergic triggers, non-allergic triggers.
Asthma and allergy - Asthma attacks (worsening of asthma symptoms) can be triggered by allergies. Allergy is the leading cause of asthma.
What is an asthma attack? - An asthma attack occurs when the small and medium-sized airways become inflamed and constricted after being exposed to a trigger.
Asthma in children - Asthma is the most common chronic condition of childhood. Asthma symptoms can interfere with many school activities for children.
Asthma and pregnancy - During pregnancy, asthma or asthma episodes will become worse for an estimated one-third of pregnant women, particularly women who have severe asthma.
Asthma in adults and older people - Identifying asthma in the elderly can be difficult because asthma symptoms can be confused with symptoms of heart or lung diseases.
What're the complications of asthma? - Uncontrolled asthma in pregnant women puts them at higher risk for complications that can include early labor, hypertension, gestational diabetes.
What are the symptoms of asthma? - The symptoms of asthma include labored breathing, constriction of the chest, coughing and gasping usually brought on by allergies.
What're the warning signs of asthma? - Most people with asthma have warning signs before symptoms appear. There are many warning signs of an asthma episode.
How is asthma diagnosed? - The diagnosis of asthma is made on the basis of typical symptoms and signs. Positive allergy tests support a diagnosis of asthma.
What're the treatments for asthma? - Treatment of asthma is aimed at avoiding known allergens and respiratory irritants and controlling symptoms and airway inflammation through medication.
What quick relief (rescue) medications cure asthma? - Short-acting beta-agonists are the most commonly used asthma rescue medications. Anticholinergics are another class of asthma drugs.
Long-term asthma control medications - Combinations of steroids and other medications are effective for both treating and preventing asthma attacks in patients with moderate to severe asthma.
What're asthma inhalers? - Most asthma drugs are inhaled using special devices or nebulizers. Two common types include dry powder asthma inhalers and metered-dose asthma inhalers.
What're asthma nebulizers? - Asthma nebulizers can be used with all classes of inhaled medications but are most commonly used with short-acting beta2 agonists and ipratropium bromide.
How to control acute asthma attacks? - Acute asthma is an acute exacerbation of wheezing, unresponsive to usually effective therapy and necessitating care in an emergency room or hospital ward.
How to manage chronic asthma symptoms? - The aims of management are to recognize asthma, to abolish symptoms, to restore normal or best possible long term airway function.
What asthma relievers are available? - Asthma reliever is a drug that provides relief from asthma symptoms and is the most commonly used asthma medication.
What asthma preventers are available? - Asthma preventers are to be used twice a day regardless of whether your child has symptoms of asthma.
What's the treatment for childhood asthma? - The goals of asthma therapy are to prevent child from having chronic and troublesome symptoms, to maintain child's lung function.
What's the treatment for asthma in the elderly? - Diagnosis and treatment of asthma can be more complicated in people age 65 and older than in those who are younger.
What can be done to prevent asthma? - Avoiding known allergens and respiratory irritants can reduce asthma symptoms. People with asthma should minimize risk for respiratory tract infections.