title: Endurance exercise training blunts the deleterious effect of high-fat feeding on whole body efficiency.
abstract: We recently showed that a week-long, high-fat diet reduced whole body exercise efficiency in sedentary men by >10% (Edwards LM, Murray AJ, Holloway CJ, Carter EE, Kemp GJ, Codreanu I, Brooker H, Tyler DJ, Robbins PA, Clarke K. FASEB J 25: 1088-1096, 2011). To test if a similar dietary regime would blunt whole body efficiency in endurance-trained men and, as a consequence, hinder aerobic exercise performance, 16 endurance-trained men were given a short-term, high-fat (70% kcal from fat) and a moderate carbohydrate (50% kcal from carbohydrate) diet, in random order. Efficiency was assessed during a standardized exercise task on a cycle ergometer, with aerobic performance assessed during a 1-h time trial and mitochondrial function later measured using (31)P-magnetic resonance spectroscopy. The subjects then underwent a 2-wk wash-out period, before the study was repeated with the diets crossed over. Muscle biopsies, for mitochondrial protein analysis, were taken at the start of the study and on the 5th day of each diet. Plasma fatty acids were 60% higher on the high-fat diet compared with moderate carbohydrate diet (P < 0.05). However, there was no change in whole body efficiency and no change in mitochondrial function. Endurance exercise performance was significantly reduced (P < 0.01), most probably due to glycogen depletion. Neither diet led to changes in citrate synthase, ATP synthase, or mitochondrial uncoupling protein 3. We conclude that prior exercise training blunts the deleterious effect of short-term, high-fat feeding on whole body efficiency.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom. L.M.Edwards@utas.edu.au
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Edwards
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Holloway
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Murray
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Knight
authors.forename: Emma E
authors.initials: EE
authors.lastname: Carter
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Kemp
authors.forename: Campbell H
authors.initials: CH
authors.lastname: Thompson
authors.forename: Damian J
authors.initials: DJ
authors.lastname: Tyler
authors.forename: Stefan
authors.initials: S
authors.lastname: Neubauer
authors.forename: Peter A
authors.initials: PA
authors.lastname: Robbins
authors.forename: Kieran
authors.initials: K
authors.lastname: Clarke
mesh_terms: D004041:Dietary Fats / Q000008:administration & dosage / Q000009:adverse effects*; D004734:Energy Metabolism / Q000187:drug effects*; D015444:Exercise; D005227:Fatty Acids / Q000097:blood; D006801:Humans; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism; D010807:Physical Endurance / Q000502:physiology*; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids