Integrative Physiology
Obesity (2009) 17 7, 1332–1339. doi:10.1038/oby.2009.2
Resistance Training Preserves Fat-free Mass Without Impacting Changes in Protein Metabolism After Weight Loss in Older Women
Wayne W. Campbell1, Mark D. Haub2, Robert R. Wolfe3, Arny A. Ferrando3, Dennis H. Sullivan3, John W. Apolzan1 and Heidi B. Iglay1
- 1Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana, USA
- 2Department of Human Nutrition, Kansas State University, Manhattan, Kansas, USA
- 3Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
Correspondence: Wayne W. Campbell (campbellw@purdue.edu.)
Received 19 August 2008; Accepted 22 December 2008; Published online 26 February 2009.
Abstract
This study assessed the effects of resistance training (RT) on energy restriction–induced changes in body composition, protein metabolism, and the fractional synthesis rate of mixed muscle proteins (FSRm) in postmenopausal, overweight women. Sixteen women (age 68 
1 years, BMI 29 1 kg/m2, mean s.e.m.) completed a 16-week controlled diet study. Each woman consumed 1.0 g protein/kg/day. At baseline (weeks B1–B3) and poststudy (weeks RT12–RT13), energy intake matched each subject's need and during weeks RT1–RT11 was hypoenergetic by 2,092 kJ/day (500 kcal/day). From weeks RT1 to RT13, eight women performed RT 3 day/week (RT group) and eight women remained sedentary (SED group). RT did not influence the energy restriction–induced decrease in body mass (SED -5.8 0.6 kg; RT -5.0 0.2 kg) and fat mass (SED -4.1 0.9 kg; RT -4.7 0.5 kg). Fat free mass (FFM) and total body water decreased in SED (-1.6 0.4 and -2.1 0.5 kg) and were unchanged in RT (-0.3 0.4 and -0.4 0.7 kg) (group-by-time, P 
0.05 and P = 0.07, respectively). Protein–mineral mass did not change in either group (SED 0.4 0.2 kg; RT 0.1 0.4 kg). Nitrogen balance, positive at baseline (2.2 0.3 g N/day), was unchanged poststudy. After body mass loss, postabsorptive (PA) and postprandial (PP) leucine turnover, synthesis, and breakdown decreased. Leucine oxidation and balance were not changed. PA and total (PA + PP) FSRm in the vastus lateralis were higher after weight loss. RT did not influence these protein metabolism responses. In summary, RT helps older women preserve FFM during body mass loss. The comparable whole-body nitrogen retentions, leucine kinetics, and FSRm between groups are consistent with the lack of differential protein–mineral mass change.
