First, have a thorough medical evaluation and obtain your doctor's permission before beginning an exercise program. Your doctor will probably prescribe you a medicine to help keep your airways open during exercise. For example, you may be instructed to take albuterol, a short-acting inhaled bronchodilator, 15 minutes before exercise to prevent symptoms for up to about four hours.
Once you receive clearance from your doctor, consider the following exercise guidelines:
Always have medication nearby for use in the event of an asthma attack. Be aware of early signs of an asthma attack, such as shortness of breath and coughing.
Take extra time (aim for 15 minutes) to warm up before exercising. This helps the airway retain a more normal size.
Prolong your cool-down. The second most likely time to experience an exercise-induced asthma attack is in the five to 10 minutes after exercise. By gradually decreasing intensity, you reduce your risk.
Be aware of your exercise environment. Avoid exposure to other asthma triggers such as pollen and pollution when exercising. A warm and humid environment (like that in a pool) reduces exposure of the lungs to cool, dry air - the suspected cause of exercise-induced asthma.
Consider exercising at the lower end of your target heart-rate range and incorporating intervals for high-intensity training to minimize your risk of an asthma attack. Choose exercises least likely to trigger an attack, such as pool swimming and walking.
Maintain adequate hydration. This will decrease mucous accumulation in the airways, thus reducing risk for an asthma attack or a future infection like bronchitis or pneumonia.
Maximize air exchange with diaphragmatic breathing. Inhale deeply through your nose and exhale through your mouth. With each inhalation you should see or feel your belly rise.
Rest when necessary and listen to what your body is telling you.
Excerpted from the article "Exercise and Asthma" from the American Counil of Exercise, www.acefitness.org.