| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, United States; , United States
2 Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
3 Medicine / Division of Endocrinolgy, University of Pittsburgh, Pittsburgh, Pennsylvania, United States; Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
4 Division of Endocrinology and Metabolism, University of Pittsburgh Department of Medicine, Pittsburgh, Pennsylvania, United States
* To whom correspondence should be addressed. E-mail: goodpaster{at}dom.pitt.edu.
We previously reported an "athlete’s paradox" in which endurance-trained athletes, who possess a high oxidative capacity and enhanced insulin sensitivity, also have higher intramyocellular lipid (IMCL) content. The purpose of this study was to determine whether moderate exercise training would increase IMCL, oxidative capacity of muscle and insulin sensitivity in previously sedentary overweight to obese, insulin resistant older subjects. Twenty-five older (66.4±0.8years) obese (BMI=30.3±0.7kg/m2) men (n=9) and women (n=16) completed a 16-week moderate but progressive exercise training program. Body weight and fat mass modestly but significantly (P<0.01) decreased. Insulin sensitivity, measured using the euglycemic-hyperinsulinemic clamp, was increased (21%, P=0.02) with modest improvements (7%, P=0.04) in aerobic fitness (VO2peak). Histochemical analyses of IMCL (Oil Red O staining), oxidative capacity (succinate dehydrogenase activity; SDH), glycogen content, capillary density and fiber type were performed on skeletal muscle biopsies. Exercise training increased IMCL by 21%. In contrast, diacylglycerol and ceramide, measure by mass-spectroscopy, were decreased (n=13, -29% and -24%, respectively,both P<0.05) with exercise training. SDH (19%), glycogen content (15%), capillary density (7%) and the percentage of type I, slow-oxidative fibers (from 50.8% to 55.7%), all P
0.05 were increased after exercise. In summary, these results extend the "athlete’s paradox" by demonstrating that chronic exercise in overweight to obese older adults improves insulin sensitivity in conjunction with favorable alterations in lipid partitioning and an enhanced oxidative capacity within muscle. Therefore, several key deleterious effects of aging and/or obesity on the metabolic profile of skeletal muscle can be reversed with only moderate increases in physical activity.
This article has been cited by other articles:
|
|
 |
|
  N. K. LeBrasseur, T. M. Schelhorn, B. L. Bernardo, P. G. Cosgrove, P. M. Loria, and T. A. Brown Myostatin Inhibition Enhances the Effects of Exercise on Performance and Metabolic Outcomes in Aged Mice J Gerontol A Biol Sci Med Sci, September 1, 2009; 64A(9): 940 - 948. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Amati, J. J. Dube, P. M. Coen, M. Stefanovic-Racic, F. G.S. Toledo, and B. H. Goodpaster Physical Inactivity and Obesity Underlie the Insulin Resistance of Aging Diabetes Care, August 1, 2009; 32(8): 1547 - 1549. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. P. J. Solomon, J. M. Haus, C. M. Marchetti, W. C. Stanley, and J. P. Kirwan Effects of exercise training and diet on lipid kinetics during free fatty acid-induced insulin resistance in older obese humans with impaired glucose tolerance Am J Physiol Endocrinol Metab, August 1, 2009; 297(2): E552 - E559. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Chomentowski, J. J. Dube, F. Amati, M. Stefanovic-Racic, S. Zhu, F. G.S. Toledo, and B. H. Goodpaster Moderate Exercise Attenuates the Loss of Skeletal Muscle Mass That Occurs With Intentional Caloric Restriction-Induced Weight Loss in Older, Overweight to Obese Adults J Gerontol A Biol Sci Med Sci, May 1, 2009; 64A(5): 575 - 580. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. Alsted, L. Nybo, M. Schweiger, C. Fledelius, P. Jacobsen, R. Zimmermann, R. Zechner, and B. Kiens Adipose triglyceride lipase in human skeletal muscle is upregulated by exercise training Am J Physiol Endocrinol Metab, March 1, 2009; 296(3): E445 - E453. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R Short Introduction to symposium proceedings: the emerging interplay among muscle mitochondrial function, nutrition, and disease Am. J. Clinical Nutrition, January 1, 2009; 89(1): 453S - 454S. [Full Text] [PDF]
|
|
|
|
 |
|
 F. Amati, J. J. Dube, C. Shay, and B. H. Goodpaster Separate and combined effects of exercise training and weight loss on exercise efficiency and substrate oxidation J Appl Physiol, September 1, 2008; 105(3): 825 - 831. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
