About 80 percent of asthma sufferers have it; about 10 percent of the population without asthma has it, too. It is called exercise-induced asthma, or exercise-induced bronchospasm (EIB). A bronchospasm occurs when the muscles in the walls of the bronchioles, or airway passages, suddenly constrict. People with preexisting asthma are very likely to develop EIB, as will athletes, especially those who train or perform in cold air, but it can strike anyone through a variety of triggers.

About Exercise-Induced Bronchospasm

Air enters the lungs through the mouth and windpipe. From there it travels into smaller branches of airways called the right and left bronchi. The bronchi further branch into bronchioles and finally into the alveoli. Dry air and irritants that enter the lungs when exercising can cause these airways to narrow and make it difficult to breathe. This is exercise-induced bronchospasm.

There is no one specific cause for EIB but several factors can trigger it. Activities like running, aerobics, and playing vigorous sports like basketball or hockey make it harder to breathe. This rapid breathing may dry out the airways, which can trigger EIB. Cold weather can trigger it because the inhaled air is drier and cooler than the air already in the lungs. Other trigger factors include smoke, smog, pollen, pet dander, respiratory infection, paints, fertilizers, herbicides, and chemicals like chlorine.

Symptoms

Symptoms of EIB may start after 5 to 20 minutes of continuous exercise. A person begins to cough and wheeze and experience shortness of breath and tightness or pain in the chest. He or she may feel especially fatigued during exercise.

To diagnose whether or not a patient has EIB, the doctor will examine the ear, nose, chest, and throat. To determine whether the symptoms are caused by EIB or another underlying medical condition, lung function tests will be conducted. A peak flow meter is used, which is a small device into which the patient exhales air with force. If the exhalation is low, the patient is given a puff or two from a bronchodilator to clear the airways and tested again. If the reading improves, it is a good indication that the patient has asthma.

A spirometry, which detects asthma and other respiratory conditions, requires the patient to take deep breaths and exhale into the tube connected to the spirometer. If the values measured are below normal for that person's age and gender, it indicates swelling and blockage in the lungs. The patient is given a bronchodilator and tested again. If the values have improved, it indicates the person suffers from asthma.

To check if allergens like dust mites, latex, pet dander, or mold are causing bronchospasms instead of just exercise, skin allergy tests are performed where the skin is pricked with the allergy-causing substances and its reactions observed.

For the majority of cases, EIB can be treated effectively with inhaled medication. Used 15 to 30 minutes before exercise, these pre-treatment inhalers open the airways quickly and keep them open for several hours. These medications include:

• A short-acting bronchodilator: taken 15 minutes before exercise it lasts four to six hours

• A mast cell stabilizer: taken 15 to 60 minutes before exercise it lasts four hours

• A longer acting bronchodilator: taken 30 minutes before exercise it lasts up to 12 hours

• An anti-leukotriene: taken daily it lasts up to 24 hours

To prevent EIB, it is advised to warm up for at least 15 minutes before exercising. If possible, exercise in a humid environment, such as by a lake or in a gym with a swimming pool. Humidity helps keep the airways of the lungs open.

Avoid exercising when suffering from cold or any other respiratory infection. Air pollutants, pet dander, and pollen should be avoided. Keep the mouth and nose covered when exercising in cold weather, since cold, dry air causes the airways to constrict.

Maintaining good health and a healthy body weight can help ease asthmatic symptoms.

Living with EIB

EIB is not curable, but it is treatable. People with a history of asthma and athletes who train under cold conditions should be careful of bronchospasm attacks and take all necessary precautions to avoid them. Coaches should be made aware if an athlete has this condition. Asthma and EIB does not have to prevent a person from exercising or participating in sports. Proper preparation and medication can help those who suffer from bronchospasms to reach their goals.