Expiratory flow limitation in youth endurance-trained and recreationally active females

Authors

Sarah Ridgeway, James Madison UniversityFollow

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Date of Graduation

8-12-2022

Semester of Graduation

Summer

Degree Name

Master of Science (MS)

Department

Department of Kinesiology

Second Advisor

Nicholas D. Luden

Third Advisor

Michael J. Saunders

Abstract

The purpose of this study was to investigate the presence of expiratory flow limitation (EFL) in endurance trained (ET) youth females compared to a recreationally active (RA) group. EFL has been reported in ET males of pubertal age, however, the presence of EFL in ET youth females is not established. Methods: Youth ET female subjects (n=9, 15.8 ± 1.1 years) and RA subjects (n=10, 16.8 ± 1.6 years) completed an incremental exercise test to exhaustion on a cycle ergometer to determine peak oxygen consumption (VO_2peak). Maximum flow volume loops (MFVL), forced vital capacity (FVC), forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC), forced expiratory flow between 25-75% of FVC (FEF_25-75%), and peak expiratory flow (PEF) were assessed pre- and post-exercise. Inspiratory capacity (IC) maneuvers, heart rate (HR), rating of perceived exertion (RPE), and rating of perceived dyspnea (RPD) were assessed in the last 20 s of each stage. EFL presence and severity was measured as a percentage of tidal volume that overlapped with the MFVL. Results: VO_2peak (ET: 3.5 ± 0.5 L/min, RA: 2.7 ± 0.5 L/min), peak power (ET: 240 ± 32.8 W, RA: 150 ± 22.6 W), peak ventilation (VE) (ET: 114.9 ± 20.4 BTPS, RA: 76.6 ± 20.8 BTPS), peak heart rate (ET: 194.4 ± 7.9 bpm, RA: 176.8 ± 17.5 bpm), RPE (ET: 18.4 ± 1.3, RA: 17.0 ± 2.0), and V_E/VO₂ (ET: 31.3 ± 4.8, RA: 27.8 ± 5.9), and V_E/VCO₂ (ET: 28.7 ± 3.9, RA: 26.7 ± 4.1) were greater in the ET group compared to the RA group (p-values < 0.05). EFL presence was significantly greater (p < 0.05) in the ET group with 7 out of 9 subjects exhibiting flow limitation compared to the RA group with 2 out of 10 exhibiting flow limitation, and was more severe in the ET group at maximal exercise (ET: 57.0 ± 36.4%, RA: 13.3 ± 32.2%, p < 0.05). Conclusions: ET youth females exhibit a greater presence and severity of EFL at maximal exercise than RA subjects that are similar in age and height. Further research should be conducted to determine if a high presence of EFL is seen throughout puberty and into adulthood in the same subjects.