If you cough or experience chest tightness, stomachache, dry throat or headache after strenuous exercise, you may be among the 12 percent of the population suffering from exercise-induced asthma.
Often called EIA, the condition occurs most often in people who have chronic asthma. It also afflicts about 40 percent of people who have only hay fever, however. Its symptoms, caused when muscular spasms or inflammation of the bronchial tubes in the lungs makes breathing difficult, usually occur after at least five minutes of strenuous exercise and may persist for 15 minutes or two hours.
Aretaeus the Cappadocian first described EIA in the second century A.D. About 30 years ago, modern physicians began to recognize that EIA occurs frequently in adults. About 20 years ago, doctors realized children also experience the condition.
Today, researchers have increased their knowledge about EIA substantially. For instance, they’ve learned that running and cycling are more likely to trigger it than kayaking or swimming. Even walking can provoke EIA in a few asthmatics. Smog, cigarette smoke and other irritants in the air increase EIA susceptibility, as does dry, cold air. Humid, warm air, on the other hand, reduces the risk. Children whose parents or siblings have asthma are more prone to EIA than those from families without asthma.
The type of exercise is also a factor. Some research suggests EIA can be avoided by engaging in less strenuous exercise or by exercising in short bursts of exertion alternating with several minutes of rest over a period of no more than 40 minutes, such as might occur during circuit weight training, for example. Exercising indoors during smog alerts also helps.
Current theories suggest water loss and heat loss from the lower respiratory tract may provoke EIA. Some researchers also have suggested that carbon dioxide loss may trigger the condition. If so, breathing into a paper bag, which forces you to inhale the carbon dioxide you’ve exhaled, might relieve symptoms. Learning to breathe slowly and deeply during exercise may be helpful as well.
Some individuals who develop nasal congestion with exercise may benefit from medications that open the nasal passageways. Using a nose spray containing agents such as oxymetazoline hydrochloride 0.05% just before exercise, or using nasal cromolyn sodium regularly, can help keep the nasal passageways open. Any blockage of the nasal passageways due to polyps, tumors or foreign bodies should be surgically corrected.
There are also other medications that can help prevent or reduce EIA. These agents can be separated into three types:
Cromolyn sodium reduces inflammation and cough and can ease bronchial reactions to air pollutants, allergens, and dry or cold air. It is most effective when administered within two hours before exercise.
Antihistamines can help block spasms of the bronchial tubes in some cases. However, the effect is mild and antihistamines cannot prevent EIA.
Bronchodilators relax the muscles of the bronchial tubes that constrict in EIA. If administered before exercise, they may open the bronchial passages enough to compensate for any bronchoconstriction induced by exercise. Bronchodilators may also be used to relieve bronchospasm once it occurs. Albuterol, terbutaline, metaproterenol and pirbuterol are perhaps the bronchodilators of choice for preventing EIA. They specifically enhance lung function, with minimal cardiovascular side effects, and provide lasting bronchodilatation for four to six hours.
With the right combination of exercise modification and medication, you can prevent EIA and enjoy the many physical and psychological benefits of regular exercise. Avoiding exercise outdoors during cold weather and smog alerts definitely can help. Exercising in short bursts followed by periods of rest may be worthwhile. Also recommended are indoor sports, such as swimming, which take place in warm, moist air.