title: The anabolic potential of dietary protein intake on skeletal muscle is prolonged by prior light-load exercise.
abstract: OBJECTIVE
  Hyperaminoacidemia stimulates myofibrillar fractional synthesis rate (myoFSR) transiently in resting skeletal muscle. We investigated whether light-load resistance exercise can extent this responsiveness.
  
  
  METHODS
  Ten healthy males exercised one leg with a light-load resistance-like exercise at 16% of 1 repetition maximum and received oral protein boluses every hour for a 10-h period. Their myoFSR was determined by [1-(13)C]-leucine incorporation. Muscle biopsies were obtained from the resting (REST) and exercised (EXC) muscles every 2.5-h in the protein-fed period.
  
  
  RESULTS
  Protein feeding significantly elevated plasma leucine and essential amino acids by an average of 39 ± 9% (mean ± SEM) and 20 ± 4%, respectively, compared to the basal concentrations: 197 ± 12 μmol L(-1) and 854 ± 35 μmol L(-1), respectively. The myoFSR was similar in EXC and REST muscles in the first 8 h (all time intervals p > 0.05). After 8 h the myoFSR dropped in the REST muscle to 0.041 ± 0.005%·h(-1), which was 65 ± 5% of the rate in EXC leg at the same time point (0.062 ± 0.004%·h(-1)) and 80 ± 14% of the level in REST leg from 0.5 to 8 h (0.056 ± 0.005%·h(-1)) (interaction p < 0.05).
  
  
  CONCLUSIONS
  Compared to rest, light-load exercise prolonged the stimulatory effect of dietary protein on muscle biosynthesis providing perspectives for a muscle restorative effect in clinical settings where strenuous activity is intolerable.
authors.affiliation: Institute of Sports Medicine, Dept. of Orthopedic Surgery M81, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Bechshoeft
authors.forename: Kasper J
authors.initials: KJ
authors.lastname: Dideriksen
authors.forename: Søren
authors.initials: S
authors.lastname: Reitelseder
authors.forename: Thomas
authors.initials: T
authors.lastname: Scheike
authors.forename: Michael
authors.initials: M
authors.lastname: Kjaer
authors.forename: Lars
authors.initials: L
authors.lastname: Holm
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000601:Amino Acids, Essential / Q000008:administration & dosage / Q000097:blood; D045930:Anabolic Agents / Q000008:administration & dosage; D001786:Blood Glucose / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000097:blood; D007930:Leucine / Q000008:administration & dosage / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism; D012146:Rest / Q000502:physiology; D055815:Young Adult
chemical_list: D000601:Amino Acids, Essential; D045930:Anabolic Agents; D001786:Blood Glucose; D004044:Dietary Proteins; D007328:Insulin; D007930:Leucine