title: Vigorous Exercise Can Cause Abnormal Pulmonary Function in Healthy Adolescents.
abstract: BACKGROUND
  Although exercise-induced bronchoconstriction is more common in adolescents with asthma, it also manifests in healthy individuals without asthma. The steady-state exercise protocol is widely used and recommended by the American Thoracic Society (ATS) as a method to diagnose exercise-induced bronchoconstriction. Airway narrowing in response to exercise is thought to be related to airway wall dehydration secondary to hyperventilation. More rigorous exercise protocols may have a role in detecting exercise-induced bronchoconstriction in those who otherwise have a normal response to steady-state exercise challenge.
  
  
  OBJECTIVE
  The objective of this study was to determine the effect of two different exercise protocols--a constant work rate protocol and a progressive ramp protocol--on pulmonary function testing in healthy adolescents. We hypothesized that vigorous exercise protocols would lead to reductions in lung function in healthy adolescents.
  
  
  METHODS
  A total of 56 healthy adolescents (mean age, 15.2 ± 3.3 [SD] years) were recruited to perform two exercise protocols: constant work rate exercise test to evaluate for exercise-induced bronchoconstriction (as defined by ATS) and standardized progressive ramp protocol. Pulmonary function abnormalities were defined as a decline from baseline in FEV1 of greater than 10%.
  
  
  RESULTS
  Ten participants (17.8%) had a significant drop in FEV1. Among those with abnormal lung function after exercise, three (30%) were after the ATS test only, five (50%) were after the ramp test only, and two (20%) were after both ATS and ramp tests.
  
  
  CONCLUSIONS
  Healthy adolescents demonstrate subtle bronchoconstriction after exercise. This exercise-induced bronchoconstriction may be detected in healthy adolescents via constant work rate or the progressive ramp protocol. In a clinical setting, ramp testing warrants consideration in adolescents suspected of having exercise-induced bronchoconstriction and who have normal responses to steady-state exercise testing.
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|2 Miller Children's Hospital, Long Beach, California; and.
authors.forename: Alladdin
authors.initials: A
authors.lastname: Abosaida
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|2 Miller Children's Hospital, Long Beach, California; and.
authors.forename: Jen Jen
authors.identifier: http://orcid.org/0000-0002-5628-8977
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|2 Miller Children's Hospital, Long Beach, California; and.
authors.forename: Eliezer
authors.initials: E
authors.lastname: Nussbaum
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|3 Institute for Clinical and Translational Science, UC Irvine, Irvine, California.
authors.forename: Szu-Yun
authors.initials: SY
authors.lastname: Leu
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|2 Miller Children's Hospital, Long Beach, California; and.
authors.forename: Terry
authors.initials: T
authors.lastname: Chin
authors.affiliation: 1 Department of Pediatrics, School of Medicine, University of California, Irvine (UC Irvine), Irvine, California.|3 Institute for Clinical and Translational Science, UC Irvine, Irvine, California.
authors.forename: Christina D
authors.initials: CD
authors.lastname: Schwindt
mesh_terms: D000293:Adolescent; D016084:Bronchoconstriction / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D012129:Respiratory Function Tests / Q000379:methods
keywords: exercise physiology; exercise testing; exercise-induced bronchoconstriction