Expiratory flow limitation under moderate hypobaric hypoxia does not influence ventilatory responses during incremental running in endurance runners

Autor:	Naoto Fujii, Yinhang Cao, Yuhei Ichikawa, Yosuke Sasaki, Takeshi Ogawa, Tsutomu Hiroyama, Takeshi Nishiyasu, Yasushi Enomoto
Jazyk:	angličtina
Rok vydání:	2019
Předmět:	Male medicine.medical_specialty Time Factors Physiology Acclimatization Flow limitation 030204 cardiovascular system & hematology endurance performance Running Incremental exercise Young Adult 03 medical and health sciences Oxygen Consumption 0302 clinical medicine Aerobic capacity Physiology (medical) Internal medicine Respiration Humans Medicine Lung volumes Respiratory Physiology Hypoxia Muscle Skeletal Lung Original Research Exercise Tolerance business.industry Altitude Endurance and Performance VO2 max Muscle Fatigue Physical Endurance Cardiology Breathing Hypobaric hypoxia Energy Metabolism Pulmonary Ventilation business respiration 030217 neurology & neurosurgery Respiratory minute volume airflow limitation Muscle Contraction Physical Conditioning Human
Zdroj:	Physiological Reports
ISSN:	2051-817X
Popis:	We tested whether expiratory flow limitation (EFL) occurs in endurance athletes in a moderately hypobaric hypoxic environment equivalent to 2500 m above sea level and, if so, whether EFL inhibits peak ventilation (urn:x-wiley:2051817X:media:phy213996:phy213996-math-0001Epeak), thereby exacerbating the hypoxia‐induced reduction in peak oxygen uptake (urn:x-wiley:2051817X:media:phy213996:phy213996-math-0002O2peak). Seventeen young male endurance runners performed incremental exhaustive running on separate days under hypobaric hypoxic (560 mmHg) and normobaric normoxic (760 mmHg) conditions. Oxygen uptake (urn:x-wiley:2051817X:media:phy213996:phy213996-math-0003O2), minute ventilation (urn:x-wiley:2051817X:media:phy213996:phy213996-math-0004E), arterial O2 saturation (SpO2), and operating lung volume were measured throughout the incremental exercise. Among the runners tested, 35% exhibited EFL (EFL group, n = 6) in the hypobaric hypoxic condition, whereas the rest did not (Non‐EFL group, n = 11). There were no differences between the EFL and Non‐EFL groups for urn:x-wiley:2051817X:media:phy213996:phy213996-math-0005Epeak and urn:x-wiley:2051817X:media:phy213996:phy213996-math-0006O2peak under either condition. Percent changes in urn:x-wiley:2051817X:media:phy213996:phy213996-math-0007Epeak (4 ± 4 vs. 2 ± 4%) and urn:x-wiley:2051817X:media:phy213996:phy213996-math-0008O2peak (−18 ± 6 vs. −16 ± 6%) from normobaric normoxia to hypobaric hypoxia also did not differ between the EFL and Non‐EFL groups (all P > 0.05). No differences in maximal running velocity, SpO2, or operating lung volume were detected between the two groups under either condition. These results suggest that under the moderate hypobaric hypoxia (2500 m above sea level) frequently used for high‐attitude training, ~35% of endurance athletes may exhibit EFL, but their ventilatory and metabolic responses during maximal exercise are similar to those who do not exhibit EFL.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e08200d4a183a8673d67aaca460e2c75 https://tsukuba.repo.nii.ac.jp/records/52157 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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