Exercise induced bronchodilation: a phenomenon more common, greater magnitude and more prolonged in older adults than in adolescents.

Objective: There are few studies in clinically healthy subjects describing and quantifying exercise-induced bronchodilation (EIB). This study aimed to describe and compare the magnitude and time course changes in post-exercise forced expired volume at the first second (FEV) in healthy adolescents, younger adults, and older adults.

Methods: Adolescent ( = 73, aged 10-17 years), younger adult ( = 35, aged 18-25 years), and older adult ( = 25, aged 35-66 years) subjects with normal spirometry z-scores completed a maximal cardiopulmonary exercise test using the standardized exponential exercise test protocol on a cycle ergometer performed at stable temperature and humidity. Spirometry was performed pre-exercise and at 1-, 3-, 5-, and 10-minutes post-exercise to determine the percentage change in FEV compared to baseline. EIB was defined as  ≥ 5% increase in post-exercise FEV.

Results: Increases in FEV at one-minute post-exercise were observed in the adolescents (1.3%) and young adults (6.0%) with FEV returning to baseline after ten minutes. Compared to the adolescents, the older adults showed significantly greater and sustained increases in FEV at 1-, 3-, 5-, and 10-minutes post-exercise (6.4, 4.6, 4.7, and 3.8%,  < 0.05). At 1-minute post exercise a significantly greater proportion of younger adults (54%,  < 0.01) and older adults (64%,  < 0.01) demonstrated EIB compared to the adolescent group (15%).

Conclusion: Healthy older adults had a higher prevalence, greater magnitude and more prolonged EIB compared to healthy adolescent and young adult subjects.