Airway obstruction during exercise and isocapnic hyperventilation in asthmatic subjects

Oscar E. Suman, Kenneth C. Beck, Mark A. Babcock, David F. Pegelow, William G. Reddan

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


We compared pulmonary mechanics measured during long-term exercise (LTX = 20 min) with long-term isocapnic hyperventilation (LTIH = 20 min) in the same asthmatic individuals (n = 6). Peak expiratory flow (PEF) and forced expiratory volume in i s (FEV1) decreased during LTX (-19.7 and -22.0%, respectively) and during LTIH (-6.66 and 10.9%, respectively). In contrast, inspiratory pulmonary resistance (RL(I)) was elevated during LTX (57.6%) but not during LTIH (9.62%). As expected, airway function deteriorated post-LTX and post-LTIH (FEV1 = -30.2 and -21.2%; RL(I) = 111.8 and 86.5%, respectively). We conclude that the degree of airway obstruction observed during LTX is of a greater magnitude than that observed during LTIH. Both modes of hyperpnea induced similar levels of airway obstruction in the posthyperpnea period. However, the greater airway obstruction during LTX suggests that a different process may be responsible for the changes in airway function during and after the two modes of hyperpnea. This finding raises questions about the equivalency of LTIH and LTX in the study of airway function during exercise-induced asthma.

Original languageEnglish (US)
Pages (from-to)1107-1113
Number of pages7
JournalJournal of Applied Physiology
Issue number3
StatePublished - Sep 1999
Externally publishedYes


  • Exercise-induced asthma
  • Pulmonary resistance

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'Airway obstruction during exercise and isocapnic hyperventilation in asthmatic subjects'. Together they form a unique fingerprint.

Cite this