title: Exercise performed immediately after fructose ingestion enhances fructose oxidation and suppresses fructose storage.
abstract: BACKGROUND
  Exercise prevents the adverse effects of a high-fructose diet through mechanisms that remain unknown.
  
  
  OBJECTIVE
  We assessed the hypothesis that exercise prevents fructose-induced increases in very-low-density lipoprotein (VLDL) triglycerides by decreasing the fructose conversion into glucose and VLDL-triglyceride and fructose carbon storage into hepatic glycogen and lipids.
  
  
  METHODS
  Eight healthy men were studied on 3 occasions after 4 d consuming a weight-maintenance, high-fructose diet. On the fifth day, the men ingested an oral (13)C-labeled fructose load (0.75 g/kg), and their total fructose oxidation ((13)CO2 production), fructose storage (fructose ingestion minus (13)C-fructose oxidation), fructose conversion into blood (13)C glucose (gluconeogenesis from fructose), blood VLDL-(13)C palmitate (a marker of hepatic de novo lipogenesis), and lactate concentrations were monitored over 7 postprandial h. On one occasion, participants remained lying down throughout the experiment [fructose treatment alone with no exercise condition (NoEx)], and on the other 2 occasions, they performed a 60-min exercise either 75 min before fructose ingestion [exercise, then fructose condition (ExFru)] or 90 min after fructose ingestion [fructose, then exercise condition (FruEx)].
  
  
  RESULTS
  Fructose oxidation was significantly (P < 0.001) higher in the FruEx (80% ± 3% of ingested fructose) than in the ExFru (46% ± 1%) and NoEx (49% ± 1%). Consequently, fructose storage was lower in the FruEx than in the other 2 conditions (P < 0.001). Fructose conversion into blood (13)C glucose, VLDL-(13)C palmitate, and postprandial plasma lactate concentrations was not significantly different between conditions.
  
  
  CONCLUSIONS
  Compared with sedentary conditions, exercise performed immediately after fructose ingestion increases fructose oxidation and decreases fructose storage. In contrast, exercise performed before fructose ingestion does not significantly alter fructose oxidation and storage. In both conditions, exercise did not abolish fructose conversion into glucose or its incorporation into VLDL triglycerides. This trial was registered at clinicaltrials.gov as NCT01866215.
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Léonie
authors.initials: L
authors.lastname: Egli
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Virgile
authors.initials: V
authors.lastname: Lecoultre
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Jérémy
authors.initials: J
authors.lastname: Cros
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Robin
authors.initials: R
authors.lastname: Rosset
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Marques
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland;
authors.forename: Philippe
authors.initials: P
authors.lastname: Schneiter
authors.affiliation: Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom; and.
authors.forename: Leanne
authors.initials: L
authors.lastname: Hodson
authors.affiliation: Centre for Research in Human Nutrition Rhône-Alpes and European Centre of Nutrition for Health, Lyon 1 University, Lyon, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Gabert
authors.affiliation: Centre for Research in Human Nutrition Rhône-Alpes and European Centre of Nutrition for Health, Lyon 1 University, Lyon, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Laville
authors.affiliation: Department of Physiology, University of Lausanne, Lausanne, Switzerland; luc.tappy@unil.ch.
authors.forename: Luc
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000328:Adult; D001642:Bicycling; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D001944:Breath Tests; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D002247:Carbon Isotopes; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism*; D005632:Fructose / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism*; D006801:Humans; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D008297:Male; D009043:Motor Activity; D010084:Oxidation-Reduction; D019308:Palmitic Acid / Q000097:blood / Q000378:metabolism; D019518:Postprandial Period; D057185:Sedentary Behavior; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002247:Carbon Isotopes; D004040:Dietary Carbohydrates; D008079:Lipoproteins, VLDL; D002245:Carbon Dioxide; D019308:Palmitic Acid; D005632:Fructose; D019344:Lactic Acid
keywords: de novo lipogenesis; energy output; fructose; gluconeogenesis; lactic acid