Document Detail

Reduced heterogeneity of muscle deoxygenation during heavy bicycle exercise.
MedLine Citation:
PMID:  15741839     Owner:  NLM     Status:  MEDLINE    
PURPOSE: This study evaluated heterogeneity of muscle O2 dynamics in a single muscle during bicycle exercise using an eight-channel near-infrared continuous wave spectroscopy (NIRcws) mapping system. METHODS: Nine healthy subjects performed bicycle exercise at fixed workloads of 20, 40, 60, 80, and 100% maximal workload for 5 min at each level. Muscle oxygenation in the vastus lateralis (VL) during and after each exercise was monitored using the NIRcws mapping system. Pulmonary O2 uptake and heart rate were monitored continuously during the experiment. Blood samples were taken to measure blood lactate concentration at 30 s after each exercise stage. RESULTS: Half time reoxygenation, the time taken to reach a value of half-maximal recovery, was significantly delayed in distal sites compared with proximal sites of VL. Conversely, muscle deoxygenation for all measurement sites increased incrementally with higher exercise workloads, and no significant difference of deoxygenation level showed within each channel. However, relative dispersion of muscle deoxygenation during exercise significantly decreased when the workload increased. Moreover, relative dispersion of muscle deoxygenation between the subjects also decreased with an increase in the workload. CONCLUSION: Muscle deoxygenation in a single muscle was more heterogeneous at lower exercise workloads, and variations of the muscle deoxygenation heterogeneity between subjects were greater at lower exercise workloads.
Ryotaro Kime; Joohee Im; Daniel Moser; Yuanqing Lin; Shoko Nioka; Toshihito Katsumura; Britton Chance
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  37     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2005 Mar 
Date Detail:
Created Date:  2005-03-02     Completed Date:  2005-05-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  412-7     Citation Subset:  IM; S    
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA.
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MeSH Terms
Bicycling / physiology*
Exercise / physiology*
Heart Rate / physiology
Muscle, Skeletal / metabolism*
Oxygen / metabolism*
Oxygen Consumption / physiology
Task Performance and Analysis
Reg. No./Substance:

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