Exercise-induced asthma is a well-known condition in both adults and children. But a new study finds that kids with no history of asthma may exhibit asthma-like symptoms after bouts of intense exercise.
The study, presented at the American Thoracic Society's international conference in New Orleans this week, included 56 healthy children, average age 15. Researchers from UC Irvine and Miller Children's Hospital in Long Beach gave each child two exercise tests -- one at a constant work rate, the other a progressive test usually done to measure aerobic capacity.
After testing for pulmonary function, 45% of the study participants had at least one abnormal result. That was seen in 14% of participants after the constant work rate test, in 20% after the progressive test, and 11% had at least one abnormal result after both tests. No substantial differences were found in the number of abnormal outcomes in the two tests.
Decreases in pulmonary function can occur when heavy exercise triggers an inflammatory response, constricting bronchial tubes.
"We did not expect to see pulmonary function abnormalities after short periods of heavy exercise in such a large number of healthy children in our subject population," said Dr. Alladdin Abosaida, lead author of the study, in a news release. "We speculate that either the inflammatory response to exercise or cellular changes that may occur as the result of dehydration of the airway surface, or both, led to mild airway obstruction."
Abosaida added that more research is needed to discover why this type of lung dysfunction might be occurring in children.
-- Jeannine Stein
Photo: Healthy children may experience asthma-like symptoms during exercise, according to a new study. Credit: Wally Skalij / Los Angeles Times