Document Detail


Femoral artery inflow in relation to external and total work rate at different knee extensor contraction rates.
MedLine Citation:
PMID:  11842074     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Whether limb blood flow is directly regulated to match the work rate, independent of the rate of contraction, remains elusive. This study therefore investigated the relationship between femoral arterial blood flow (FABF; Doppler ultrasound) and "external" (applied load) as well as "total" [external + "internal" (potential and kinetic energy changes of the moving lower leg)] work rate, during steady-state one-legged, dynamic, knee extensor exercise (1L-KEE) in the sitting position at different contraction rates. Ten subjects performed 1L-KEE at 30, 60, and 90 contractions/min (cpm) 1) at constant resistive loads of 0.2 and 0.5 kg inducing incremental external work rates (study I) and 2) at different relative resistive loads inducing constant external work rates of 9 and 18 W (study II). Moreover, 3) six subjects performed 1L-KEE at 60 and 100 cpm at incremental total work rates of 40, 50, 60, and 70 W (study III). In study I, FABF increased (P < 0.001) with increasing contraction frequency and external work rate, for each resistive load. In study II, FABF increased (P < 0.001) with increasing contraction frequency for each constant external work rate. Of major importance in study III, however, was that FABF, although increasing linearly with the total work rate, was not different (P = not significant) between contraction rates, at the total work rates of 40, 50, 60, and 70 W, respectively. Furthermore, FABF correlated linearly and positively with both the external and total work rate for each contraction frequency. In conclusion, the findings support the concept that leg blood flow during 1L-KEE in a normal knee extensor ergometer is matched directly in relation to the total work rate and metabolic activity, irrespective of the contraction frequency. The rate of contraction seems erroneously to influence the results only when it is related to the external work rate without taking into account the internal work component.
Authors:
Takuya Osada; Göran Rådegran
Related Documents :
9862534 - Passive and active exercises increase cerebral blood flow velocity in young, healthy in...
16817964 - Regional muscle oxygenation differences in vastus lateralis during different modes of i...
18473094 - Virtx - evaluation of a computer-based training system for mobile c-arm systems in trau...
20570604 - Effect of acute unloaded arm versus leg cycling exercise on the soleus h-reflex in adul...
9876294 - Post-exercise changes in blood pressure, heart rate and rate pressure product at differ...
9782544 - Blood redistribution and circulatory responses to submaximal arm exercise in persons wi...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  92     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2002 Mar 
Date Detail:
Created Date:  2002-02-13     Completed Date:  2002-05-07     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1325-30     Citation Subset:  IM    
Affiliation:
The Copenhagen Muscle Research Centre, University of Copenhagen, and Rigshospitalet, DK-2100 Copenhagen Ø, Denmark. DENTACMAC@aol.com
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Femoral Artery / physiology*,  ultrasonography
Humans
Knee / physiology*
Leg / blood supply
Male
Muscle Contraction / physiology*
Regional Blood Flow / physiology
Time Factors
Weight Lifting / physiology

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


Previous Document:  Brain activation by central command during actual and imagined handgrip under hypnosis.
Next Document:  Biopsy coupled to quantitative immunofluorescence: a new method to study the human vascular endothel...