title: Independent effects of endurance training and weight loss on peak fat oxidation in moderately overweight men: a randomized controlled trial.
abstract: Endurance training increases peak fat oxidation (PFO) during exercise, but whether this is independent of changes in body weight is not known. The aim of the present study was to investigate the effects of endurance training with or without weight loss or a diet-induced weight loss on PFO and on key skeletal muscle mitochondrial proteins involved in fat oxidation. Sixty moderately overweight, sedentary but otherwise healthy men were randomized to 12 wk of training (T), diet (D), training and increased caloric intake (T-iD), or continuous sedentary control (C). Isoenergetic deficits corresponding to 600 kcal/day were comprised of endurance exercise for T and caloric restriction for D. T-iD completed similar training but was not in 600 kcal deficit because of dietary replacement. PFO and the exercise intensity at which this occurred (FatMax) were measured by a submaximal exercise test and calculated by polynomial regression. As intended by study design, a similar weight loss was observed in T (-5.9 ± 0.7 kg) and D (-5.2 ± 0.8 kg), whereas T-iD (-1.0 ± 0.5 kg) and C (0.1 ± 0.6 kg) remained weight stable. PFO increased to a similar extent with 42% in T [0.16 g/min; 95% confidence intervals (CI): 0.02; 0.30, P = 0.02] and 41% in T-iD (0.16 g/min; 95% CI: 0.01; 0.30, P = 0.04) compared with C, but did not increase in D (P = 0.96). In addition, the analysis of covariance showed that changes in both PFO (0.10 g/min; 95% CI: 0.03; 0.17, P = 0.03) and FatMax (6.3% V̇o2max; 95% CI: 1.4; 11.3, P < 0.01) were independently explained by endurance training. In conclusion, endurance training per se increases PFO in moderately overweight men.
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Pernille
authors.initials: P
authors.lastname: Nordby
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and madsrl@sund.ku.dk.
authors.forename: Mads
authors.initials: M
authors.lastname: Rosenkilde
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Thorkil
authors.initials: T
authors.lastname: Ploug
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Karina
authors.initials: K
authors.lastname: Westh
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Michael
authors.initials: M
authors.lastname: Feigh
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Ninna B
authors.initials: NB
authors.lastname: Nielsen
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and Center for Healthy Aging, University of Copenhagen, Denmark.
authors.forename: Jørn W
authors.initials: JW
authors.lastname: Helge
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Denmark; and.
authors.forename: Bente
authors.initials: B
authors.lastname: Stallknecht
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D005081:Exercise Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000503:physiopathology* / Q000628:therapy*; D010084:Oxidation-Reduction; D064797:Physical Conditioning, Human / Q000379:methods; D010807:Physical Endurance; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
keywords: diet; exercise; fat metabolism; skeletal muscle