title: Branched-chain amino acid supplementation before squat exercise and delayed-onset muscle soreness.
abstract: The authors examined the effect of branched-chain amino acid (BCAA) supplementation on squat-exercise-induced delayed-onset muscle soreness (DOMS) using 12 young, healthy, untrained female participants. The experiment was conducted with a crossover double-blind design. In the morning on the exercise-session day, the participants ingested either BCAA (isoleucine:leucine:valine = 1:2.3:1.2) or dextrin at 100 mg/kg body weight before the squat exercise, which consisted of 7 sets of 20 squats/set with 3-min intervals between sets. DOMS showed a peak on Days 2 and 3 in both trials, but the level of soreness was significantly lower in the BCAA trial than in the placebo. Leg-muscle force during maximal voluntary isometric contractions was measured 2 d after exercise (Day 3), and the BCAA supplementation suppressed the muscle-force decrease (to ~80% of the value recorded under the control conditions) observed in the placebo trial. Plasma BCAA concentrations, which decreased after exercise in the placebo trial, were markedly elevated during the 2 hr postexercise in the BCAA trial. Serum myoglobin concentration was increased by exercise in the placebo but not in the BCAA trial. The concentration of plasma elastase as an index of neutrophil activation appeared to increase after the squat exercise in both trials, but the change in the elastase level was significant only in the placebo trial. These results suggest that muscle damage may be suppressed by BCAA supplementation.
authors.affiliation: Dept. of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Shimomura
authors.forename: Asami
authors.initials: A
authors.lastname: Inaguma
authors.forename: Satoko
authors.initials: S
authors.lastname: Watanabe
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Muramatsu
authors.forename: Gustavo
authors.initials: G
authors.lastname: Bajotto
authors.forename: Juichi
authors.initials: J
authors.lastname: Sato
authors.forename: Noriko
authors.initials: N
authors.lastname: Shimomura
authors.forename: Hisamine
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Mawatari
mesh_terms: D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology*; D001628:Beverages; D018592:Cross-Over Studies; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries* / Q000378:metabolism; D009211:Myoglobin / Q000097:blood; D018375:Neutrophil Activation; D010196:Pancreatic Elastase / Q000097:blood; D055815:Young Adult
chemical_list: D000597:Amino Acids, Branched-Chain; D009211:Myoglobin; D010196:Pancreatic Elastase