title: Ten weeks of branched-chain amino acid supplementation improves select performance and immunological variables in trained cyclists.
abstract: We examined if supplementing trained cyclists (32 ± 2 year, 77.8 ± 2.6 kg, and 7.4 ± 1.2 year training) with 12 g/day (6 g/day L-Leucine, 2 g/day L-Isoleucine and 4 g/day L-Valine) of either branched-chain amino acids (BCAAs, n = 9) or a maltodextrin placebo (PLA, n = 9) over a 10-week training season affected select body composition, performance, and/or immune variables. Before and after the 10-week study, the following was assessed: (1) 4-h fasting blood draws; (2) dual X-ray absorptiometry body composition; (3) Wingate peak power tests; and (4) 4 km time-trials. No group × time interactions existed for total lean mass (P = 0.27) or dual-leg lean mass (P = 0.96). A significant interaction existed for body mass-normalized relative peak power (19 % increase in the BCAA group pre- to post-study, P = 0.01), and relative mean power (4 % increase in the BCAA group pre- to post-study, P = 0.01). 4 km time-trial time to completion approached a significant interaction (P = 0.08), as the BCAA group improved in this measure by 11 % pre- to post-study, though this was not significant (P = 0.15). There was a tendency for the BCAA group to present a greater post-study serum BCAA: L-Tryptophan ratio compared to the PLA group (P = 0.08). A significant interaction for neutrophil number existed (P = 0.04), as there was a significant 18 % increase within the PLA group from the pre- to post-study time point (P = 0.01). Chronic BCAA supplementation improves sprint performance variables in endurance cyclists. Additionally, given that BCAA supplementation blunted the neutrophil response to intense cycling training, BCAAs may benefit immune function during a prolonged cycling season.
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: Wesley C
authors.initials: WC
authors.lastname: Kephart
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: Taylor D
authors.initials: TD
authors.lastname: Wachs
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: R Mac
authors.initials: RM
authors.lastname: Thompson
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: C
authors.initials: C
authors.lastname: Brooks Mobley
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: Carlton D
authors.initials: CD
authors.lastname: Fox
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: McDonald
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Ferguson
authors.affiliation: Wichita State University, Wichita, KS, USA.
authors.forename: Kaelin C
authors.initials: KC
authors.lastname: Young
authors.affiliation: Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Nie
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.|Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, AL, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Martin
authors.affiliation: Endurance Company, LLC, Bloomington, IL, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Company
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA.|Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, AL, USA.
authors.forename: David D
authors.initials: DD
authors.lastname: Pascoe
authors.affiliation: Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Arnold
authors.affiliation: MusclePharm Sports Science Institute, Denver, CO, USA.
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Moon
authors.affiliation: School of Kinesiology, Molecular and Applied Sciences Laboratory, Auburn University, 301 Wire Road, Office 286, Auburn, AL, 36849, USA. mdr0024@auburn.edu.|Edward Via College of Osteopathic Medicine, Auburn Campus, Auburn, AL, USA. mdr0024@auburn.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Roberts
mesh_terms: D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D056352:Athletes; D001823:Body Composition; D019587:Dietary Supplements / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology*; D010807:Physical Endurance; D055815:Young Adult
chemical_list: D000597:Amino Acids, Branched-Chain
keywords: Cycling; Immunity; Isoleucine; Leucine; Peak power; Valine