Exercise-related asthma is a tightening of the airways in the lungs triggered by vigorous or prolonged exercise.
When breathing normally, air is taken in through the nose. The nose performs two important functions that prevent asthmatic episodes: warming and humidifying the air. While exercising, people tend to breathe through their mouths, bypassing these important functions. As dry, cool air enters the lungs, the airways, called bronchi, can become inflamed as a response to the air temperature and humidity. This inflammation causes the airways to narrow, restricting airflow and making it hard to get enough oxygen into the blood.
Due to these internal reactions, a person will experience coughing, a tight feeling in the chest, wheezing, and unusual fatigue. Although asthma should be taken seriously and can be fatal, if the symptoms are properly managed, athletes can continue to perform. With inhalant medications, physical activity need not be avoided.
Exercise-related asthma affects 12%–15% of the population of the United States, including people who do not otherwise show symptoms of asthma or allergy. Even among nonasthmatic individuals, 3%–10% experience exercise-related asthma. It is particularly common among athletes who play winter or cold weather sports, such as ice hockey, cross-country skiing, and figure skating. Among competitive athletes in these sports, rates have been found to be between 35% and 50%.
Asthma affects 5%–10% of people in the United States and nearly 300 million individuals worldwide. It is most common among developed nations, likely because of factors such as increased pollution and urbanization. In the United States, asthma is more common among African Americans and Hispanics, and although genetic factors may be important, environmental factors likely play a greater role, especially in morbidity and mortality rates related to asthma. Asthma is found more often in boys during childhood, but after puberty it is more common among females. Overall, two-thirds of asthma cases are diagnosed before age 18, and about half of these cases decrease or disappear by the end of childhood. Exercise-related asthma has been reported in up to 90% of asthmatics.
Risk factors for exercise-related asthma include:
Exercise-related asthma is caused by cool, dry air entering the lungs and the related bronchial reaction. Normal breathing is predominantly done through the nose, which filters out irritants and warms and humidifies the incoming air, but when exercising, people tend to breathe through the mouth, thus allowing cooler, dryer air to enter the lungs. The airways inside the lungs respond to this type of air with spasms and a decrease in size, which results in symptoms that are identical to an asthma attack, such as coughing, shortness of breath, a tightening feeling in the chest, wheezing, and unusual fatigue. Typically these symptoms manifest shortly after exercise begins or shortly after exercise ceases.
Like other asthma symptoms, exercise-related asthma symptoms are typically treated using two different types of inhalant medications. The first kind are known as short-acting beta-2 agonists. These typically begin working in 15–20 minutes and last for four to six hours. The second kind are known as long-acting beta-2 agonists. These can last for up to 12 hours, but usually take at least 30 minutes to begin alleviating symptoms, so these are typically taken in the morning.
The prognosis for exercise-related asthma is generally good. If monitored and managed properly, it should not stand in the way of athletic goals or an active lifestyle. In fact, many well-known athletes, such as basketball star Dennis Rodman, Olympic gold-medalist Jackie Joyner-Kersee, and Steelers running-back Jerome Bettis, continued to compete and succeed despite their asthma.
Patients who experience exercise-related asthma should not avoid physical activity but rather should work with their physicians to develop a plan to treat and prevent asthma symptoms. Patients should also take this plan seriously because according to the World Health Organization, approximately 250,000 deaths around the globe are due to asthma each year, and in the United States alone approximately 500,000 people are hospitalized each year because of asthma symptoms.
Exercise-related asthma can be prevented by following a physician-directed medical treatment plan and by reducing factors during exercise that can trigger asthmatic episodes. One way to do this is by warming and humidifying the air that enters the lungs, as would happen during normal breathing. This can be accomplished during exercise by purposeful nose breathing or by breathing through a mask or scarf. Another risk factor can be reduced by avoiding exercise when the air is particularly cold or dry or when the pollen count is particularly high. Choosing certain sports over others can also help. Sports that tend to involve longer periods of aerobic exercise such as running or soccer should be avoided, whereas sports that involve short bursts of energy, such as football or volleyball, are less likely to produce symptoms. A proper warm-up of 6–10 minutes before beginning an athletic activity is also recommended.
See also Asthma .
Gershwin, M. Eric., and Timothy E. Albertson, eds. Bron-chial Asthma: A Guide for Practical Understanding and Treatment 6th ed. New York: Springer, 2012.
Rundell, Kenneth W., Randall L. Wilber, and Robert Lemanske. Exercise-Induced Asthma: Pathophysiology and Treatment. Champaign, IL: Human Kinetics, 2002.
Bonini, Matteo, and Paolo Palange. “Exercise-Induced Bronchoconstriction: New Evidence in Pathogenesis, Diagnosis, and Treatment.” Asthma Research and Practice 1, no. 2 (2015):.
Martin, Neil, et al. “Airway Dysfunction and Inflammation in Pool and Non-Pool Based Elite International Athletes with Symptoms Suggesting Exercise-Induced Asthma.” Medicine and Science in Sports and Exercise 44, no. 8 (August 2012): 1433–9.
Garry, Joseph P. “Exercise-Induced Asthma.” Medscape. http://emedicine.medscape.com/article/1938228-overview (accessed March 2, 2017).
Dryden Donna M., et al. “Exercise-Induced Bronchoconstriction and Asthma.” Agency for Healthcare Research and Quality. http://www.ahrq.gov/downloads/pub/evidence/pdf/eibeia/eibeia.pdf (accessed March 2, 2017).
Parsons, Jonathan P., et al. “An Official American Thoracic Society Clinical Practice Guideline: Exercise-Induced Bronchoconstriction.” American Thoracic Society. https://www.thoracic.org/statements/resources/allergy-asthma/exercise-induced-bronchoconstriction.pdf (accessed March 2, 2017).
Allergy & Asthma Foundation of America, 8201 Corporate Dr., Ste. 1000, Landover, MD, 20785, (800) 727-8462, firstname.lastname@example.org, http://www.aafa.org/ .
Allergy & Asthma Network, 8229 Boone Blvd., Vienna, VA, 22182, (800) 878-4403, Fax: (703) 288-5271, http://www.aanma.org .
National Athletic Trainers' Association, 1620 Valwood Pkwy., Ste. 115, Carrollton, TX, 75006, (214) 637-6282, Fax: (214) 637-2206, http://www.nata.org .
National Heart, Lung, and Blood Institute, P.O. Box 30105, Bethesda, MD, 20824, (301) 592-8573, nhlbiinfo@nhlbi. nih.gov, http://www.nhlbi.nih.gov .
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