Document Detail


Kinetics of oxygenation in inactive forearm muscle during ramp leg cycling.
MedLine Citation:
PMID:  14757996     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study was carried out to determine whether hemodynamics in inactive forearm muscle during ramp leg cycling is affected from the ventilatory threshold (VT) and respiratory compensation point (RCP), at which the rate of increase in ventilation (VE) against power output begins to increase abruptly. Change in hemodynamics was evaluated by change in oxygenation index (difference between concentrations of oxygenated hemoglobin and deoxygenated hemoglobin, HbD) measured using near-infrared spectrometry (NIRS). Each subject (n=9) performed 4-min constant-work-rate leg cycling and subsequent ramp leg cycling at an increasing rate of 10 watts.min(-1) in power output. The work rates at VT, RCP and peak oxygen uptake (VO(2 peak)) were 107 +/- 11, 172 +/- 21 and 206 +/- 20 watts, respectively. The rates of increase in VE between 10-watt leg cycling, VT, RCP and VO(2 peak) were 0.19 +/- 0.03, 0.44 +/- 0.07 and 1.32 +/- 0.47 l.min(-1).watts(-1), respectively. In one subject, HbD started to decrease during ramp exercise from the VT, and the rate of decrease increased at a high intensity of exercise. In eight subjects, although no decrease in HbD from the VT was observed, HbD showed a sudden drop at a high intensity of exercise. The work rate at which HbD began to decrease at a high intensity of exercise was 174 +/- 23 watts. This work rate was not significantly different from that at the RCP and was significantly correlated with that at the RCP (r=0.72, P<0.05). The results suggest that the abrupt increase in VE from the RCP affects hemodynamics, resulting in a decrease in HbD in inactive forearm muscle.
Authors:
Hisayoshi Ogata; Abiti Reyihan; Tokuo Yano
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Journal of physiological anthropology and applied human science     Volume:  23     ISSN:  1345-3475     ISO Abbreviation:  J Physiol Anthropol Appl Human Sci     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-02-03     Completed Date:  2004-05-05     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100930389     Medline TA:  J Physiol Anthropol Appl Human Sci     Country:  Japan    
Other Details:
Languages:  eng     Pagination:  7-17     Citation Subset:  IM    
Affiliation:
Laboratory of Exercise Physiology, Graduate School of Education, Hokkaido University, Japan. hogata@edu.hokudai.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Adult
Blood Pressure
Exercise / physiology*
Forearm / physiology
Humans
Male
Muscle, Skeletal / physiology*
Oxygen / blood*
Oxygen Consumption
Pulmonary Ventilation / physiology*
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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