title: Effects of a longitudinal training program on responses to exercise in overweight men.
abstract: OBJECTIVE
  The aim of this study was to determine how training modifies metabolic responses and lipid oxidation in overweight young male subjects.
  
  
  METHODS
  Eleven overweight subjects were selected for a 4-month endurance training program. Before and after the training period, they cycled for 60 minutes at 50% of their VO(2)max after an overnight fast or 3 hours after eating a standardized meal. Various metabolic and endocrine parameters, and respiratory exchange ratio values were evaluated.
  
  
  RESULTS
  Exercise-induced plasma norepinephrine concentration increases were similar before and after training in fasted or fed conditions. After food intake, exercise promoted a decrease in plasma glucose and a higher increase in epinephrine than in fasting conditions. The increase in epinephrine after the meal was more marked after training (264 +/- 32 vs. 195 +/- 35 pg/mL). Training lowered the resting plasma nonesterified fatty acids. During exercise, changes in glycerol were similar to those found before training. Lipid oxidation during exercise was higher in fasting than in fed conditions (15.5 +/- 1.4 vs. 22.3 +/- 1.7 g/h). Training did not significantly increase fat oxidation when exercise was performed in fed conditions, but it did in fasting conditions (18.6 +/- 1.4 vs. 27.2 +/- 1.8 g/h).
  
  
  CONCLUSIONS
  Endurance training decreased plasma nonesterified fatty acids, cholesterol, and insulin concentrations. Training increased lipid oxidation during exercise, in fasting conditions, and not when exercise was performed after the meal. During exercise in overweight subjects, the fasting condition seems more suited to oxidizing fat and maintaining glucose homeostasis than a 3-hour wait after a standard meal.
authors.affiliation: Department of Adaptation to Exercise, Laboratory of Medical and Clinical Pharmacology, Faculty of Medicine, INSERM Unit 317, Toulouse, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Crampes
authors.forename: Fabrice
authors.initials: F
authors.lastname: Marion-Latard
authors.forename: Alexia
authors.initials: A
authors.lastname: Zakaroff-Girard
authors.forename: Isabelle
authors.initials: I
authors.lastname: De Glisezinski
authors.forename: Isabelle
authors.initials: I
authors.lastname: Harant
authors.forename: Claire
authors.initials: C
authors.lastname: Thalamas
authors.forename: Vladimir
authors.initials: V
authors.lastname: Stich
authors.forename: Daniel
authors.initials: D
authors.lastname: Rivière
authors.forename: Max
authors.initials: M
authors.lastname: Lafontan
authors.forename: Michel
authors.initials: M
authors.lastname: Berlan
mesh_terms: D000328:Adult; D001642:Bicycling; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D002149:Energy Intake; D004837:Epinephrine / Q000097:blood; D015444:Exercise; D005215:Fasting; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005502:Food; D005990:Glycerol / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007700:Kinetics; D015227:Lipid Peroxidation; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption; D010807:Physical Endurance; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D002784:Cholesterol; D005990:Glycerol; D009638:Norepinephrine; D004837:Epinephrine