The Prevalence of Airways Hyperresponsiveness in Members of an Exercise Training Facility

Athletes have a high prevalence (11-50%) of exercise-induced asthma, which may be caused by the hyperventilation accompanying repetitive bouts of strenuous exercise. We hypothesized that recreational exercisers would display a similar trend. Eucapnic voluntary hyperventilation (EVH) bronchoprovocation (breathing 21% O2, 5% CO2, and 74% N2 at 60% of MVV for 5 minutes) was performed to determine the prevalence of airways hyperresponsiveness (AHR) in adults (n = 212, 146 males, mean ± standard deviation, age 32 ± 10 years) who exercised regularly (10 ± 10 years, 31 ± 28% of their lives): none had a previous diagnosis of asthma. AHR was defined by at least a 10%, 20%, or 25% decline in FEV1, FEF25-75, or PEFR, respectively, by spirometry at 1, 5, 10, and 15 minutes post-EVH. Forty-one of 212 (19%) tested positive for AHR: 20 of 41 (49%) were positive by FEV1, 28 of 41 (68%) by FEF25-75, and 27 of 41 (66%) by PEFR. Comparing responders with nonresponders: pre-EVH lung function was equivalent, except for FEV1, which was reduced (p