title: Exercise training elevates RMR during moderate but not severe dietary restriction in obese male rats.
abstract: This study examined the effects of 11 wk of exercise training (E) on resting O2 uptake (RMR) and the composition of diet-induced weight loss in obese male Sprague-Dawley rats (n = 48). The rats underwent one of three levels of dietary treatment: ad libitum (AL), moderate restriction (MR), and severe restriction (SR). Compared with AL-CC (cage confined; 647 +/- 13 g), the AL-E (84% of AL-CC), MR-CC (77%), MR-E (77%), SR-CC (63%), and SR-E (63%) groups were all reduced in body mass. At the MR level, E significantly reduced fat mass (FM; MR-CC 73 +/- 5, MR-E 45 +/- 5 g) and increased water mass (WM; MR-CC 307 +/- 5, MR-E 329 +/- 5 g) compared with CC. In contrast, no significant differences existed between the SR-CC and SR-E groups. Exercise training did not result in conservation of protein mass at any level of dietary intake. Exercise training significantly elevated RMR (on a kg0.75 basis) by approximately 7% for the AL-E and MR-E groups compared with their respective dietary counterparts. These findings may help reconcile the conflicting results present in the literature with respect to the effects of exercise training during diet-induced weight loss. That is, studies using relatively severe dietary restrictions are less likely to demonstrate exercise-induced changes in RMR, FM, and WM than those employing moderate dietary restrictions.
authors.affiliation: Department of Psychology, University of Wisconsin, Madison 53706.
authors.forename: D L
authors.initials: DL
authors.lastname: Ballor
mesh_terms: D000818:Animals; D001481:Basal Metabolism / Q000502:physiology; D001823:Body Composition; D001835:Body Weight; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D008297:Male; D009765:Obesity / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D010101:Oxygen Consumption; D010805:Physical Conditioning, Animal; D051381:Rats; D011919:Rats, Inbred Strains