title: Intramyocellular lipid variations in active older men: relationship with aerobic fitness.
abstract: OBJECTIVE
  Intramyocellular lipid (IMCL) variations in older men are poorly explored. In young adults, IMCL can be influenced by both diet and exercise interventions; this flexibility is related to aerobic fitness. We evaluated in active older adults the influence of maximal aerobic capacity on short-term diet and exercise-induced variations in IMCL stores.
  
  
  METHODS
  Intramyocellular lipids were measured by (1) H magnetic resonance spectroscopy ((1) H-MRS) after a 3-day fat depletion-replenishment diet (IMCL(FDR) ) and immediately after a 2-h exercise at 50% VO(2) max (IMCL(FDR) (_) (EX) ). To further explore diet influence, the protocol was repeated after a high-fat diet (HF), with both pre- and post-exercise measurements (IMCL(HF) and IMCL(HF) (_) (EX) ).
  
  
  RESULTS
  In active older men (69.8 ± 5.2 years), IMCL(FDR) was lowered by exercise (IMCL(FDR) = 3.45 ± 1.52 vs. IMCL(FDR) (_) (EX) = 2.74 ± 1.15 mmol kg(-1) wet weight, P < 0.05), and exercise-induced variations were correlated to the initial store (P < 0.05, r = -0.72). IMCL(FDR) was linked with aerobic fitness (P < 0.05, r = 0.76), when adjusted by fat mass. IMCL(HF) was lower than IMCL(FDR) (P < 0.05), decreased after exercise (P < 0.05) and varied also as a function of initial store (P < 0.05, r = -0.89), but without link with aerobic fitness. Finally, diet-induced IMCL store variations were positively linked to aerobic fitness (P < 0.05, r = 0.89).
  
  
  CONCLUSIONS
  Variations of the IMCL stores in physically active older adults appear related to aerobic fitness, with similarly fast adaptation to short-term interventions combining diet and exercise as young active adults.
authors.affiliation: University Lyon 1, CarMeN, U1060 INSERM, INSA Lyon, INRA, Lyon, France.
authors.forename: D
authors.initials: D
authors.lastname: Rouffet
authors.forename: C
authors.initials: C
authors.lastname: Villars
authors.forename: R
authors.initials: R
authors.lastname: Fissoune
authors.forename: D
authors.initials: D
authors.lastname: Sappey-Marinier
authors.forename: M
authors.initials: M
authors.lastname: Laville
authors.forename: D
authors.initials: D
authors.lastname: Ibarrola
authors.forename: M
authors.initials: M
authors.lastname: Sothier
authors.forename: M-F
authors.initials: MF
authors.lastname: Monnet
authors.forename: M
authors.initials: M
authors.lastname: Ovize
authors.forename: M
authors.initials: M
authors.lastname: Bonnefoy
authors.forename: C
authors.initials: C
authors.lastname: Boesch
authors.forename: E
authors.initials: E
authors.lastname: Canet-Soulas
mesh_terms: D000222:Adaptation, Physiological; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D018752:Diet, Fat-Restricted; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D005080:Exercise Test; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010809:Physical Fitness; D012737:Sex Factors; D013997:Time Factors
chemical_list: D004041:Dietary Fats