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Date of Graduation


Document Type


Degree Name

Master of Science (MS)


Department of Kinesiology


Stephanie P. Kurti-Luden

Nicholas D. Luden

Michael J. Saunders


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 (VO2peak). 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 (FEF25-75%), 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: VO2peak (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 VE/VO2 (ET: 31.3 ± 4.8, RA: 27.8 ± 5.9), and VE/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.

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