| Muscle metabolism during graded quadriceps exercise in man. | |
| | |
MedLine Citation:
|
PMID: 17379639 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The aim of the study was to examine local muscle metabolism in response to graded exercise when the involved muscle mass is too small to elicit marked hormonal changes and local blood flow restriction. Nine healthy overnight fasted male subjects performed knee extension exercise with both thighs kicking at 25% of maximal power (Wmax) for 45 min (23+/-1% of pulmonary) followed by 35 min of kicking with one thigh at 65% and the other at 85% W(max) (40+/-1% ). Primed constant infusion of [U-13C] palmitate and [2H5]glycerol was carried out. Blood was sampled from a femoral artery and both femoral veins, and thigh blood flow was determined by thermodilution. Muscle biopsies were obtained from m. vastus lateralis of both thighs. From rest through exercise at 25, 65 and 85% Wmax the thigh blood flow (0.3+/-0.1, 2.5+/-0.2, 3.5+/-0.2, 4.1+/-0.3 l min(-1)) and oxygen uptake (0.02+/-0.01, 0.27+/-0.03, 0.48+/-0.04, 0.55+/-0.05 l min(-1)) increased (P<0.05). The plasma fatty acids oxidized in the thigh (5+/-1, 114+/-15, 162+/-30, 180+/-31 micromol min(-1)) increased (P<0.05) with exercise intensity, whereas the total thigh fat oxidation (19+/-6, 312+/-64, 356+/-93, 323+/-120 micromol min(-1)) increased (P<0.05) from rest, but remained unchanged through exercise. The thigh glycerol uptake (1+/-1, 16+/-4, 24+/-10, 39+/-8 micromol min(-1)) increased significantly from rest through exercise at 25-65 and 85% Wmax, respectively. Glucose uptake and glycogen breakdown always increased with exercise intensity. In conclusion, in the presence of a high blood flow and oxygen supply and only small hormonal changes, total fat oxidation in muscle increases from rest to light exercise, but then remains constant with exercise intensity up to heavy exercise. However, with increasing exercise intensity, oxidation of plasma free fatty acids increases and accordingly oxidation of other fat sources decreases. These findings are in contrast to whole body measurements performed during graded exercise involving a large muscle mass during which fat oxidation peaks at around 60% of . |
| | |
Authors:
|
Jørn W Helge; Bente Stallknecht; Erik A Richter; Henrik Galbo; Bente Kiens |
Related Documents
:
|
9615869 - Effect of a sports food bar on fat utilisation and exercise duration. 11319629 - Impact of high-intensity exercise on energy expenditure, lipid oxidation and body fatness. 21393469 - Conditioning of the achilles tendon via ankle exercise improves correlations between so... 22005099 - Ventilatory inefficiency as a limiting factor for exercise in patients with copd. 21432569 - Evaluation of ventilatory threshold and its relation to exercise habits among japanese. 12629559 - Strength training for obesity prevention in midlife women. 17366959 - Electromyographical analysis of selected lower extremity muscles during 5 unilateral we... 6842909 - Comparison of airway responsiveness to exercise and histamine inhalation in asthmatics. 17190179 - Control of rapid heart rate changes for electrocardiographic analysis: implications for... |
Publication Detail:
|
Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't Date: 2007-03-22 |
Journal Detail:
|
Title: The Journal of physiology Volume: 581 ISSN: 0022-3751 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 2007 Jun |
Date Detail:
|
Created Date: 2007-06-15 Completed Date: 2007-08-09 Revised Date: 2009-11-18 |
Medline Journal Info:
|
Nlm Unique ID: 0266262 Medline TA: J Physiol Country: England |
Other Details:
|
Languages: eng Pagination: 1247-58 Citation Subset: IM |
Affiliation:
|
Copenhagen Muscle Research Centre, Department of Biomedical Sciences, Panum Institute, Blegdamsvej 3, Dk 2200 n, Copenhagen, Denmark. jhelge@mfi.ku.dk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Carbohydrate Metabolism* Carbon Isotopes Epinephrine / blood Exercise / physiology* Glucose / metabolism Glycerol / administration & dosage, blood, pharmacokinetics Glycogenolysis Humans Insulin / blood Lipid Metabolism* Male Muscle Contraction* Norepinephrine / blood Oxidation-Reduction Oxygen Consumption* Palmitic Acid / administration & dosage, blood, pharmacokinetics Physical Endurance / physiology* Quadriceps Muscle / blood supply, metabolism* Regional Blood Flow |
| Chemical | |
Reg. No./Substance:
|
0/Carbon Isotopes; 11061-68-0/Insulin; 50-99-7/Glucose; 51-41-2/Norepinephrine; 51-43-4/Epinephrine; 56-81-5/Glycerol; 57-10-3/Palmitic Acid |
| Comments/Corrections | |
Comment In:
|
J Physiol. 2007 Jun 15;581(Pt 3):886
[PMID:
17478527
]
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Kv2 subunits underlie slowly inactivating potassium current in rat neocortical pyramidal neurons.
Next Document: Regulation of membrane potential and fluid secretion by Ca2+-activated K+ channels in mouse submandi...