From weekend warriors to superstars, all types of athletes experience exercise-induced asthma. They include world-class competitors like NFL star Jerome "The Bus" Bettis and six-time Olympic gold medalist swimmer Amy Van Dyken.
WebMD consulted the experts to find out the answers to these questions, as well as tips for controlling symptoms of exercise-induced asthma -- whether you're a casual athlete or a superstar.
What is Exercise-Induced Asthma?
Even many people who never experience asthma symptoms at other times have exercise-induced asthma, experts say.
"Exercise-induced asthma occurs in almost everyone who has chronic asthma, but there is a separate group of people who have what we call exercise-induced bronchospasm," says Timothy J. Craig, MD, chair of the American Academy of Allergy, Asthma and Immunology's Sports Medicine Committee.
These people, explains Craig, don't have what is considered "true" asthma. They don't have inflammation in their lungs. Nor do they experience symptoms when exposed to common triggers, like animals, pollen or mold.
"So unlike most people who have asthma and get exercise-induced symptoms, these individuals don't have true asthma, but when they exercise, they experience the symptoms of asthma," Craig tells WebMD.
Exercise-induced asthma, experienced by up to 13% of the U.S. population, occurs when the airways narrow, making breathing difficult. Why some athletes have exercise-induced asthma and others don't isn't entirely clear.
"The causes vary, but are usually associated with loss of heat or water, or both, from the lungs during exercise, because of the increased ventilation of dry and cool air," says Michael G. Miller, EdD, a spokesperson for the National Athletic Trainers Association.
People with exercise-induced asthma have airways that are overly sensitive to sudden changes in temperature and humidity, especially when breathing colder, drier air, according to the American Academy of Allergy, Asthma and Immunology (AAAAI).
During strenuous activity, people tend to breathe through their mouths. Mouth breathing allows cold, dry air directly into the lungs, without benefit of the warmth and moisture that nose breathing supplies. As a result, air is moistened to only 60-70% relative humidity. Nose-breathing, meanwhile, warms and saturates air to about 80 to 90% humidity.
The symptoms of exercise-induced asthma are similar to those of chronic asthma, explains Miller. They include:
These symptoms usually begin after several minutes of exercise and peak about 10 minutes into a workout, or sooner.
Preventing and Treating Exercise-Induced Asthma
How can these symptoms be prevented and treated, so asthma doesn't become an excuse to avoid exercise?
Here are some tips for reducing the symptoms of exercise-induced asthma:
- Be sure to warm up before working out. "A proper warm-up for at least 10 minutes with a gradual increase in intensity can help prevent symptoms," says Miller.
- Take precautions when it's chilly outside. "If it's cold, cover your mouth and nose to warm the air," says Miller. Or "move to indoor areas that are well-ventilated and have humidified, warm air."
- Use an inhaler. Inhalers contain albuterol, a beta-agonist bronchodilator. This class of drugs is effective in 80% to 90% of people with exercise-induced asthma. As a preventive therapy, it should be taken about 15 minutes before exercise. The effects can last for up to four to six hours. Your inhaler can also be used to relieve asthma symptoms after they flare.
If warming up and using albuterol don't prevent symptoms, there may be more to your exercise-induced asthma than you think.
Is it Exercise-Induced Asthma?
Are you really experiencing exercise-induced asthma, or is it chronic asthma in disguise?
"It depends, and that's one of the difficulties," says Craig. "Does a person truly have exercise-induced asthma, or is their asthma unstable and just manifesting with exercise?"
It might be chronic asthma if your asthma symptoms continue to flare after taking albuterol, or if they are triggered by things like cigarette smoke and pet dander.
"If the effects of albuterol only last for a short while, you may have underlying significant inflammation and not realize it," says Craig. "That means you have poorly controlled asthma, and you need to be seen by a physician and possibly be on an anti-inflammatory agent on a regular basis."
Sports for Avoiding Exercise-Induced Asthma
When it comes to exercise-induced asthma, warmer is better.
"It seems to be associated with mainly people who are, for instance, skaters in cold, dry areas, or skiers doing really excessive exercise in a cold and dry environment," says Craig. "The cold and dry air is one of the greatest stimuli for inducing bronchospasm."
Along with cold-weather activity, sports with sustained periods of running or exertion are more likely to trigger exercise-induced asthma. They include:
- Field hockey
- Long-distance running
- Cross-country skiing
According to the AAAAI, sports that are less likely to trigger exercise-induced asthma symptoms include:
- Leisure biking
- Free downhill skiing
- Short-distance track and field events
Whatever your sport of choice, exercise-induced asthma -- or even chronic asthma -- is no excuse to park it on the couch.
At the Olympic level,20% of elite athletes have asthma. In fact, at the 1998 Winter Olympics in Nagano, Japan, 23% of the Olympians were shown to have exercise-induced asthma after testing.
But exercise-induced asthma doesn't have to slow you down. At the 1996 Olympics in Atlanta, Georgia, nearly 30% of U.S. Olympians who had asthma or took asthma medications won team or individual medals in competition, performing just as well as non-asthmatic athletes.
Exercise-Induced Asthma: Tips for Kids
Diagnosing exercise-induced asthma in children can be difficult because the symptoms can be subtle.
For instance, kids with exercise-induced asthma might:
- Complain of not being able to run as fast as their friends.
- Express a dislike for sports because they can't compete as well as the other kids.
- Avoid physical activities altogether.
If your child is reluctant to engage in sports or other physical activities, consult your pediatrician.
Treatment of exercise-induced asthma can help keep your child active.
"I don't like to make invalids out of my asthma patients," says Richard Honsinger, MD, of the Los Alamos Medical Care Clinic in New Mexico. "If you have a child who has exercise-induced asthma, work with the teacher and send albuterol to school so your child can be pre-treated with albuterol before they go out to recess. This is often the way to get children to engage in normal activities."
Send a letter to school with the medicine, or schedule a visit with the school nurse, your child's teacher, coach, or gym teacher to discuss important aspects of exercise-induced asthma. These include:
- The nature of your child's exercise-induced asthma.
- Medications used to prevent symptoms and how to use them properly.
- Other techniques to prevent attacks, like warming up before recess.
- Warning signs of an asthma episode.
- Contact information in case of emergency, including a phone number for your child's physician.
More Exercise, Less Asthma
Last but not least, when it comes to exercise-induced asthma, your overall health can play an important role.
"Asthma severity does correlate with obesity, and the better shape you are in, the better your asthma can be controlled," says Craig. "Research shows that going through conditioning is beneficial for asthma, both in quality of life and in controlling symptoms.
"Exercise can improve both physical health and emotional well-being, even in people with exercise-induced asthma. Whether you are a weekend warrior or an Olympian, you can compete and participate in sports and activities to your fullest ability -- just be sure to bring your inhaler along.