You are not logged in.

Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans

De Bock, K., Richter, E. A., Russell, Aaron, Eijnde, B. O., Derave, W., Ramaekers, M., Konickz, E., Leger, B., Verhaeghe, J. and Hespel, P. 2005, Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans, Journal of applied physiology, vol. 564, no. 2, pp. 649-660, doi: 10.1113/jphysiol.2005.083170.

Attached Files
Name Description MIMEType Size Downloads

Title Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans
Author(s) De Bock, K.
Richter, E. A.
Russell, AaronORCID iD for Russell, Aaron orcid.org/0000-0002-7323-9501
Eijnde, B. O.
Derave, W.
Ramaekers, M.
Konickz, E.
Leger, B.
Verhaeghe, J.
Hespel, P.
Journal name Journal of applied physiology
Volume number 564
Issue number 2
Start page 649
End page 660
Publisher American Physiological society
Place of publication Bethesda, Md.
Publication date 2005
ISSN 8750-7587
1522-1601
Keyword(s) dietary carbohydrates
fasting
triglycerides
insulin release
lipid degradation
Summary The effects were compared of exercise in the fasted state and exercise with a high rate of carbohydrate intake on intramyocellular triglyceride (IMTG) and glycogen content of human muscle. Using a randomized crossover study design, nine young healthy volunteers participated in two experimental sessions with an interval of 3 weeks. In each session subjects performed 2 h of constant-load bicycle exercise (∼75% VO2max ), followed by 4 h of controlled recovery. On one occasion they exercised after an overnight fast (F), and on the other (CHO) they received carbohydrates before (∼150 g) and during (1 g (kg bw)−1 h−1) exercise. In both conditions, subjects ingested 5 g carbohydrates per kg body weight during recovery. Fibre type-specific relative IMTG content was determined by Oil red O staining in needle biopsies from m. vastus lateralis before, immediately after and 4 h after exercise. During F but not during CHO, the exercise bout decreased IMTG content in type I fibres from 18 ± 2% to 6 ± 2% (P= 0.007) area lipid staining. Conversely, during recovery, IMTG in type I fibres decreased from 15 ± 2% to 10 ± 2% in CHO, but did not change in F. Neither exercise nor recovery changed IMTG in type IIa fibres in any experimental condition. Exercise-induced net glycogen breakdown was similar in F and CHO. However, compared with CHO (11.0 ± 7.8 mmol kg−1 h−1), mean rate of postexercise muscle glycogen resynthesis was 3-fold greater in F (32.9 ± 2.7 mmol kg−1 h−1, P= 0.01). Furthermore, oral glucose loading during recovery increased plasma insulin markedly more in F (+46.80 μU ml−1) than in CHO (+14.63 μU ml−1, P= 0.02). We conclude that IMTG breakdown during prolonged submaximal exercise in the fasted state takes place predominantly in type I fibres and that this breakdown is prevented in the CHO-fed state. Furthermore, facilitated glucose-induced insulin secretion may contribute to enhanced muscle glycogen resynthesis following exercise in the fasted state.
Language eng
DOI 10.1113/jphysiol.2005.083170
Field of Research 060199 Biochemistry and Cell Biology not elsewhere classified
Socio Economic Objective 970106 Expanding Knowledge in the Biological Sciences
HERDC Research category C1.1 Refereed article in a scholarly journal
ERA Research output type C Journal article
Copyright notice ©2005, The Physiological Society
Persistent URL http://hdl.handle.net/10536/DRO/DU:30009121

Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 52 times in TR Web of Science
Scopus Citation Count Cited 59 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 614 Abstract Views, 0 File Downloads  -  Detailed Statistics
Created: Mon, 13 Oct 2008, 15:51:44 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.