PURPOSE: Expiratory flow limitation (EFL) can occur in healthy young women during exercise. We questioned whether the occurrence and severity of EFL were related to aerobic fitness or anatomical factors. METHODS: Twenty-two healthy young (<40 yr) women performed a progressive cycle test to exhaustion. The subjects' maximum expiratory flow-volume curve was compiled from several effort-graded vital capacity maneuvers before and after exercise. The maximum expiratory flow-volume curve, along with inspiratory capacity maneuvers, was used to determine lung volumes and expiratory flows and to quantify EFL. To determine relative airway size, we used a ratio sensitive to both airway size and lung volume, called the dysanapsis ratio. The subjects were partitioned into two groups based upon the appearance of >5% EFL. RESULTS: Ten subjects showed EFL during exercise. Forced vital capacities (4.4 ± 0.4 vs 3.7 ± 0.4 L, P < 0.001) and forced expiratory flows for any given lung volume were significantly larger in the non-expiratory flow-limited (NEFL) group. The NEFL group's dysanapsis ratio was significantly larger than that of the EFL group (0.27 ± 0.06 vs 0.21 ± 0.04, respectively, P < 0.05), indicating larger airways in the NEFL group. There was no difference between the NEFL and EFL groups with respect to maximal aerobic capacity (50.8 ± 10.0 vs 46.7 ± 5.9 mL·kg(-1)·min(-1), respectively, P = 0.264). At peak exercise, the NEFL group had a significantly higher end-expiratory lung volume than the EFL group (40.1% ± 4.8% vs 33.7% ± 5.7% FVC, respectively, P < 0.05). CONCLUSIONS: We conclude that EFL in women can largely be explained by anatomical factors that influence the capacity to generate flow and volume during exercise rather than fitness per se.
PURPOSE: Expiratory flow limitation (EFL) can occur in healthy young women during exercise. We questioned whether the occurrence and severity of EFL were related to aerobic fitness or anatomical factors. METHODS: Twenty-two healthy young (<40 yr) women performed a progressive cycle test to exhaustion. The subjects' maximum expiratory flow-volume curve was compiled from several effort-graded vital capacity maneuvers before and after exercise. The maximum expiratory flow-volume curve, along with inspiratory capacity maneuvers, was used to determine lung volumes and expiratory flows and to quantify EFL. To determine relative airway size, we used a ratio sensitive to both airway size and lung volume, called the dysanapsis ratio. The subjects were partitioned into two groups based upon the appearance of >5% EFL. RESULTS: Ten subjects showed EFL during exercise. Forced vital capacities (4.4 ± 0.4 vs 3.7 ± 0.4 L, P < 0.001) and forced expiratory flows for any given lung volume were significantly larger in the non-expiratory flow-limited (NEFL) group. The NEFL group's dysanapsis ratio was significantly larger than that of the EFL group (0.27 ± 0.06 vs 0.21 ± 0.04, respectively, P < 0.05), indicating larger airways in the NEFL group. There was no difference between the NEFL and EFL groups with respect to maximal aerobic capacity (50.8 ± 10.0 vs 46.7 ± 5.9 mL·kg(-1)·min(-1), respectively, P = 0.264). At peak exercise, the NEFL group had a significantly higher end-expiratory lung volume than the EFL group (40.1% ± 4.8% vs 33.7% ± 5.7% FVC, respectively, P < 0.05). CONCLUSIONS: We conclude that EFL in women can largely be explained by anatomical factors that influence the capacity to generate flow and volume during exercise rather than fitness per se.
Authors: Paolo B Dominelli; Glen E Foster; Giulio S Dominelli; William R Henderson; Michael S Koehle; Donald C McKenzie; A William Sheel Journal: J Physiol Date: 2013-04-15 Impact factor: 5.182
Authors: Paolo B Dominelli; Yannick Molgat-Seon; Derek Bingham; Philippa M Swartz; Jeremy D Road; Glen E Foster; A William Sheel Journal: J Appl Physiol (1985) Date: 2015-09-10
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Authors: Yannick Molgat-Seon; Paolo B Dominelli; Andrew H Ramsook; Michele R Schaeffer; Stéfan Molgat Sereacki; Glen E Foster; Lee M Romer; Jeremy D Road; Jordan A Guenette; A William Sheel Journal: J Appl Physiol (1985) Date: 2017-12-14
Authors: Paolo B Dominelli; Yannick Molgat-Seon; Glen E Foster; Giulio S Dominelli; Hans C Haverkamp; William R Henderson; A William Sheel Journal: Respir Physiol Neurobiol Date: 2015-09-18 Impact factor: 1.931
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