Among the researchers' findings was that a common long-term inhalant may lose its effectiveness over time and may need to be supplemented with other medications for people who have exercise-induced asthma.

Exercise-induced asthma is just one type of the disease and is also know as mild or intermittent asthma. It is seldom life-threatening. About 10 to 15 percent of people with asthma first experience symptoms either during exercise or shortly after physical activity. Some people who have the symptoms when exercising never have any other asthma problems, but nearly everyone who has been diagnosed with asthma gets bouts of exercise-induced asthma when they work out, particularly if they exercise in cold weather.

In that case, doctors often turn to a long-acting drug called salmeterol, sold under the trade name Serevent. Like albuterol, salmeterol is inhaled. It acts directly on the bronchioles in the lungs to prevent their narrowing during bouts of exercise-induced asthma. The advantage of salmeterol is that its protection lasts for up to 12 hours.