title: Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion.
abstract: OBJECTIVE
  It has been demonstrated that branched-chain amino acids (BCAA) transaminase activation occurs simultaneously with exercise-induced muscle glycogen reduction, suggesting that BCAA supplementation might play an energetic role in this condition. This study aimed to test whether BCAA supplementation enhances exercise capacity and lipid oxidation in glycogen-depleted subjects.
  
  
  METHODS
  Using a double-blind cross-over design, volunteers (N.=7) were randomly assigned to either the BCAA (300 mg . kg . day -1) or the placebo (maltodextrine) for 3 days. On the second day, subjects were submitted to an exercise-induced glycogen depletion protocol. They then performed an exhaustive exercise test on the third day, after which time to exhaustion, respiratory exchange ratio (RER), plasma glucose, free fatty acids (FFA), blood ketones and lactate were determined. BCAA supplementation promoted a greater resistance to fatigue when compared to the placebo (+17.2%). Moreover, subjects supplemented with BCAA showed reduced RER and higher plasma glucose levels during the exhaustive exercise test.
  
  
  CONCLUSIONS
  In conclusion, BCAA supplementation increases resistance to fatigue and enhances lipid oxidation during exercise in glycogen-depleted subjects.
authors.affiliation: School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, SP, Brazil. gualano@usp.br
authors.forename: A B
authors.initials: AB
authors.lastname: Gualano
authors.forename: T
authors.initials: T
authors.lastname: Bozza
authors.forename: P
authors.initials: P
authors.lastname: Lopes De Campos
authors.forename: H
authors.initials: H
authors.lastname: Roschel
authors.forename: A
authors.initials: A
authors.lastname: Dos Santos Costa
authors.forename: M
authors.initials: M
authors.lastname: Luiz Marquezi
authors.forename: F
authors.initials: F
authors.lastname: Benatti
authors.forename: A
authors.initials: A
authors.lastname: Herbert Lancha Junior
mesh_terms: D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism*; D010807:Physical Endurance / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology; D055815:Young Adult
chemical_list: D000597:Amino Acids, Branched-Chain; D005230:Fatty Acids, Nonesterified; D006003:Glycogen