Fat metabolism and acute resistance exercise in trained men

• Published in: Journal of applied physiology (1985) 2007-05, Vol.102 (5), p.1767-1772
• Main Authors: Ormsbee, Michael J, Thyfault, John P, Johnson, Emily A, Kraus, Raymond M, Choi, Myung Dong, Hickner, Robert C
• Format: Article
• Language: English
• Subjects: Adult; Basal Metabolism; Biological and medical sciences; Blood; Body Composition; Calorimetry, Indirect; Clinical outcomes; Cross-Over Studies; Energy Metabolism; Exercise; Exercise - physiology; Fatty Acids, Nonesterified - metabolism; Fundamental and applied biological sciences. Psychology; Glycerol - metabolism; Human body; Humans; Lipolysis; Male; Men; Metabolism; Microdialysis; Oils & fats; Oxidation; Oxidation-Reduction; Physical Fitness - physiology; Regional Blood Flow; Respiratory Mechanics; Subcutaneous Fat, Abdominal - blood supply; Subcutaneous Fat, Abdominal - metabolism; Tissues
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00704.2006

1 Human Performance Laboratory, Department of Exercise and Sport Science, College of Health and Human Performance, 2 Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina; and 3 Departments of Nutritional Sciences and Internal Medicine, University of Missouri, and Harry S. Truman Veterans Affairs Hospital, Columbia, Missouri Submitted 22 June 2006 ; accepted in final form 15 January 2007 The purpose of this study was to investigate the effect of acute resistance exercise (RE) on lipolysis within adipose tissue and subsequent substrate oxidation to better understand how RE may contribute to improvements in body composition. Lipolysis and blood flow were measured in abdominal subcutaneous adipose tissue via microdialysis before, during, and for 5 h following whole body RE as well as on a nonexercise control day (C) in eight young (24 ± 0.7 yr), active (>3 RE session/wk for at least 2 yr) male participants. Fat oxidation was measured immediately before and after RE via indirect calorimetry for 45 min. Dialysate glycerol concentration (an index of lipolysis) was higher during (RE: 200.4 ± 38.6 vs. C: 112.4 ± 13.1 µmol/l, 78% difference; P = 0.02) and immediately following RE (RE: 184 ± 41 vs. C: 105 + 14.6 µmol/l, 75% difference; P = 0.03) compared with the same time period on the C day. Energy expenditure was elevated in the 45 min after RE compared with the same time period on the C day (RE: 104.4 ± 6.0 vs. C: 94.5 ± 4.0 kcal/h, 10.5% difference; P = 0.03). Respiratory exchange ratio was lower (RE: 0.71 ± 0.004 vs. C: 0.85 ± .03, 16.5% difference; P = 0.004) and fat oxidation was higher (RE: 10.2 ± 0.8 vs. C: 5.0 ± 1.0 g/h, 105% difference; P = 0.004) following RE compared with the same time period on the C day. Therefore, the mechanism behind RE contributing to improved body composition is in part due to enhanced abdominal subcutaneous adipose tissue lipolysis and improved whole body fat oxidation and energy expenditure in response to RE. adipose tissue; fat oxidation; lipolysis; microdialysis; resistance exercise; resting metabolic rate Address for reprint requests and other correspondence: R. C. Hickner, Human Performance Laboratory, Dept. of Exercise and Sport Science, Dept. of Physiology, Brody School of Medicine, 363 Ward Sports Medicine Bldg., East Carolina Univ., Greenville, NC 27858 (e-mail: hicknerr{at}ecu.edu )