Impact of varying physical activity levels on airway sensitivity and bronchodilation in healthy humans

Joshua R. Smith, Stephanie P. Kurti, Ariel M. Johnson, Sarah A. Kolmer, Craig Harms

Research output: Contribution to journalArticlepeer-review


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, FEV1and 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.

Original languageEnglish (US)
Pages (from-to)1287-1293
Number of pages7
JournalApplied Physiology, Nutrition and Metabolism
Issue number12
StatePublished - Aug 14 2015


  • Airway responsiveness
  • Hypertonic saline
  • Lung volume
  • Pulmonary function
  • Sex differences

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Nutrition and Dietetics
  • Physiology (medical)


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