| Effect of inspiratory resistive loading on control of ventilation during progressive exercise. | |
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MedLine Citation:
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PMID: 3104283 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Eight healthy volunteers performed gradational tests to exhaustion on a mechanically braked cycle ergometer, with and without the addition of an inspiratory resistive load. Mean slopes for linear ventilatory responses during loaded and unloaded exercise [change in minute ventilation per change in CO2 output (delta VE/delta VCO2)] measured below the anaerobic threshold were 24.1 +/- 1.3 (SE) = l/l of CO2 and 26.2 +/- 1.0 l/l of CO2, respectively (P greater than 0.10). During loaded exercise, decrements in VE, tidal volume, respiratory frequency, arterial O2 saturation, and increases in end-tidal CO2 tension were observed only when work loads exceeded 65% of the unloaded maximum. There was a significant correlation between the resting ventilatory response to hypercapnia delta VE/delta PCO2 and the ventilatory response to VCO2 during exercise (delta VE/delta VCO2; r = 0.88; P less than 0.05). The maximal inspiratory pressure generated during loading correlated with CO2 sensitivity at rest (r = 0.91; P less than 0.05) and with exercise ventilation (delta VE/delta VCO2; r = 0.83; P less than 0.05). Although resistive loading did not alter O2 uptake (VO2) or heart rate (HR) as a function of work load, maximal VO2, HR, and exercise tolerance were decreased to 90% of control values. We conclude that a modest inspiratory resistive load reduces maximum exercise capacity and that CO2 responsiveness may play a role in the control of breathing during exercise when airway resistance is artificially increased. |
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Authors:
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A D D'Urzo; K R Chapman; A S Rebuck |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 62 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1987 Jan |
Date Detail:
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Created Date: 1987-05-15 Completed Date: 1987-05-15 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 134-40 Citation Subset: IM; S |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Carbon Dioxide / physiology* Heart Rate Humans Hypercapnia / physiopathology Male Oxygen / blood Physical Exertion* Pulmonary Gas Exchange Respiration* Tidal Volume |
| Chemical | |
Reg. No./Substance:
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124-38-9/Carbon Dioxide; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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