|
|
||||||||
INVITED REVIEW
Nutrition Research Institute Maastricht (NUTRIM), Departments of Movement Sciences and Human Biology, Maastricht University, 6200 MD Maastricht, The Netherlands
Fat and carbohydrate are the principal substrates that fuel aerobic ATP synthesis in skeletal muscle. Most endogenous fat is stored as triacylglycerol in subcutaneous and deep visceral adipose tissue. Smaller quantities of triacylglycerol are deposited as lipid droplets inside skeletal muscle fibers. The potential role of intramyocellular triacylglycerol (IMTG) as a substrate source during exercise in humans has recently regained much of its interest because of the proposed functional relationship between IMTG accumulation and the development of skeletal muscle insulin resistance. Exercise likely represents an effective means to prevent excess IMTG accretion by stimulating its rate of oxidation. However, there is much controversy on the actual contribution of the IMTG pool as a substrate source during exercise. The apparent discrepancy in the literature likely stems from methodological difficulties that have been associated with the methods used to estimate IMTG oxidation during exercise. However, recent studies using stable isotope methodology, 1H-magnetic resonance spectroscopy, and electron and/or immunofluorescence microscopy all support the contention that the IMTG pool can function as an important substrate source during exercise. Although more research is warranted, IMTG mobilization and/or oxidation during exercise seem to be largely determined by exercise intensity, exercise duration, macronutrient composition of the diet, training status, gender, and/or age. In addition, indirect evidence suggests that the capacity to mobilize and/or oxidize IMTG is substantially impaired in an obese and/or Type 2 diabetic state. As we now become aware that skeletal muscle has an enormous capacity to oxidize IMTG stores during exercise, more research is warranted to develop combined exercise, nutritional, and/or pharmacological interventions to effectively stimulate IMTG oxidation in sedentary, obese, and/or Type 2 diabetes patients.
muscle metabolism; intramuscular triglycerides; intramyocellular lipid; insulin resistance; endurance training
This article has been cited by other articles:
![]() |
R. Trepp, M. Fluck, C. Stettler, C. Boesch, M. Ith, R. Kreis, H. Hoppeler, H. Howald, J.-P. Schmid, P. Diem, et al. Effect of GH on human skeletal muscle lipid metabolism in GH deficiency Am J Physiol Endocrinol Metab, June 1, 2008; 294(6): E1127 - E1134. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. J. Dube, F. Amati, M. Stefanovic-Racic, F. G. S. Toledo, S. E. Sauers, and B. H. Goodpaster Exercise-induced alterations in intramyocellular lipids and insulin resistance: the athlete's paradox revisited Am J Physiol Endocrinol Metab, May 1, 2008; 294(5): E882 - E888. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Moro, S. Bajpeyi, and S. R. Smith Determinants of intramyocellular triglyceride turnover: implications for insulin sensitivity Am J Physiol Endocrinol Metab, February 1, 2008; 294(2): E203 - E213. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. G. Trapp, D. J. Chisholm, and S. H. Boutcher Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2370 - R2375. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. C. Devries, S. A. Lowther, A. W. Glover, M. J. Hamadeh, and M. A. Tarnopolsky IMCL area density, but not IMCL utilization, is higher in women during moderate-intensity endurance exercise, compared with men Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2336 - R2342. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. De Bock, T. Dresselaers, B. Kiens, E. A. Richter, P. Van Hecke, and P. Hespel Evaluation of intramyocellular lipid breakdown during exercise by biochemical assay, NMR spectroscopy, and Oil Red O staining Am J Physiol Endocrinol Metab, July 1, 2007; 293(1): E428 - E434. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Magkos, B. W. Patterson, B. S. Mohammed, and B. Mittendorfer A single 1-h bout of evening exercise increases basal FFA flux without affecting VLDL-triglyceride and VLDL-apolipoprotein B-100 kinetics in untrained lean men Am J Physiol Endocrinol Metab, June 1, 2007; 292(6): E1568 - E1574. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Stellingwerff, H. Boon, R. A. M. Jonkers, J. M. Senden, L. L. Spriet, R. Koopman, and L. J. C. van Loon Significant intramyocellular lipid use during prolonged cycling in endurance-trained males as assessed by three different methodologies Am J Physiol Endocrinol Metab, June 1, 2007; 292(6): E1715 - E1723. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Cheema, H. Abas, B. Smith, A. O'Sullivan, M. Chan, A. Patwardhan, J. Kelly, A. Gillin, G. Pang, B. Lloyd, et al. Progressive Exercise for Anabolism in Kidney Disease (PEAK): A Randomized, Controlled Trial of Resistance Training during Hemodialysis J. Am. Soc. Nephrol., May 1, 2007; 18(5): 1594 - 1601. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Roepstorff, M. Donsmark, M. Thiele, B. Vistisen, G. Stewart, K. Vissing, P. Schjerling, D. G. Hardie, H. Galbo, and B. Kiens Sex differences in hormone-sensitive lipase expression, activity, and phosphorylation in skeletal muscle at rest and during exercise Am J Physiol Endocrinol Metab, November 1, 2006; 291(5): E1106 - E1114. [Abstract] [Full Text] [PDF] |
||||
![]() |
J S Volek, C E Forsythe, and W J Kraemer Nutritional aspects of women strength athletes Br. J. Sports Med., September 1, 2006; 40(9): 742 - 748. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Gardan, F. Gondret, and I. Louveau Lipid metabolism and secretory function of porcine intramuscular adipocytes compared with subcutaneous and perirenal adipocytes Am J Physiol Endocrinol Metab, August 1, 2006; 291(2): E372 - E380. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Sriwijitkamol, C. Christ-Roberts, R. Berria, P. Eagan, T. Pratipanawatr, R. A. DeFronzo, L. J. Mandarino, and N. Musi Reduced Skeletal Muscle Inhibitor of {kappa}B{beta} Content Is Associated With Insulin Resistance in Subjects With Type 2 Diabetes: Reversal by Exercise Training Diabetes, March 1, 2006; 55(3): 760 - 767. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. P. Holloway, V. Bezaire, G. J. F. Heigenhauser, N. N. Tandon, J. F. C. Glatz, J. J. F. P. Luiken, A. Bonen, and L. L. Spriet Mitochondrial long chain fatty acid oxidation, fatty acid translocase/CD36 content and carnitine palmitoyltransferase I activity in human skeletal muscle during aerobic exercise J. Physiol., February 15, 2006; 571(1): 201 - 210. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Magkos, D. C. Wright, B. W. Patterson, B. S. Mohammed, and B. Mittendorfer Lipid metabolism response to a single, prolonged bout of endurance exercise in healthy young men Am J Physiol Endocrinol Metab, February 1, 2006; 290(2): E355 - E362. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Kiens Skeletal Muscle Lipid Metabolism in Exercise and Insulin Resistance Physiol Rev, January 1, 2006; 86(1): 205 - 243. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. J. C. van Loon, M. Thomason-Hughes, D. Constantin-Teodosiu, R. Koopman, P. L. Greenhaff, D. G. Hardie, H. A. Keizer, W. H. M. Saris, and A. J. M. Wagenmakers Inhibition of adipose tissue lipolysis increases intramuscular lipid and glycogen use in vivo in humans Am J Physiol Endocrinol Metab, September 1, 2005; 289(3): E482 - E493. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. B. Kritchevsky, B. J. Nicklas, M. Visser, E. M. Simonsick, A. B. Newman, T. B. Harris, E. M. Lange, B. W. Penninx, B. H. Goodpaster, S. Satterfield, et al. Angiotensin-Converting Enzyme Insertion/Deletion Genotype, Exercise, and Physical Decline JAMA, August 10, 2005; 294(6): 691 - 698. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |