title: Impact of varying physical activity levels on airway sensitivity and bronchodilation in healthy humans.
abstract: The purpose of this study was to determine if the amount of physical activity influences airway sensitivity and bronchodilation in healthy subjects across a range of physical activity levels. Thirty healthy subjects (age, 21.9 ± 2.6 years; 13 men/17 women) with normal pulmonary function reported to the laboratory on 2 separate occasions where they were randomized to breathe either hypertonic saline (HS) (nebulized hypertonic saline (25%) for 20 min) or HS followed by 5 deep inspirations (DIs), which has been reported to bronchodilate the airways. Pulmonary function tests (PFTs) were performed prior to both conditions and following the HS breathing or 5 DIs. Moderate to vigorous physical activity (MVPA) level was measured via accelerometer worn for 7 days. Following the HS breathing, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) significantly decreased from baseline by -11.8% ± 8.4% and -9.3% ± 6.7%, respectively. A 2-segment linear model determined significant relationships between MVPA and percent change in FEV1 (r = 0.50) and FVC (r = 0.55). MVPA above ∼497 and ∼500 min/week for FEV1 and FVC, respectively, resulted in minor additional improvements (p > 0.05) in PFTs following the HS breathing. Following the DIs, FEV1 and FVC decreased (p < 0.05) by -7.3% ± 8.6% and -5.7% ± 5.7%, respectively, from baseline, but were not related (p > 0.05) to MVPA. In conclusion, these data demonstrate that higher MVPA levels attenuated airway sensitivity but not bronchodilation in healthy subjects.
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.|Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Smith
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.|Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Stephanie P
authors.initials: SP
authors.lastname: Kurti
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.|Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Ariel M
authors.initials: AM
authors.lastname: Johnson
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.|Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Kolmer
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.|Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Harms
mesh_terms: D056044:Actigraphy; D000280:Administration, Inhalation; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D064368:Healthy Volunteers; D006801:Humans; D001239:Inhalation; D007615:Kansas; D016014:Linear Models; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008176:Lung Volume Measurements; D008297:Male; D008954:Models, Biological; D009043:Motor Activity; D009330:Nebulizers and Vaporizers; D011897:Random Allocation; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage*; D013997:Time Factors; D014797:Vital Capacity; D055815:Young Adult
chemical_list: D001993:Bronchodilator Agents; D012462:Saline Solution, Hypertonic
keywords: airway responsiveness; différences liées au sexe; fonction pulmonaire; hypertonic saline; lung volume; pulmonary function; sensibilité des voies aériennes; sex differences; solution saline hypertonique; volume pulmonaire