Ten weeks of branched-chain amino acid supplementation improves select performance and immunological variables in trained cyclists

No Thumbnail Available
Authors
Kephart, Wesley C.
Wachs, Taylor D.
Mac Thompson, R.
Mobley, C. Brooks
Fox, Carlton D.
McDonald, James R.
Ferguson, Brian S.
Young, Kaelin C.
Nie, Ben
Martin, Jeffrey S.
Issue Date
2016-03
Type
Article
Language
en_US
Keywords
Leucine , Isoleucine , Valine , Cycling , Peak power , Immunity
Research Projects
Organizational Units
Journal Issue
Alternative Title
Abstract

We examined if supplementing trained cyclists (32 +/- A 2 year, 77.8 +/- A 2.6 kg, and 7.4 +/- A 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 x 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.

Description
Click on the DOI link to access the article (may not be free).
Citation
Wesley C. Kephart, Taylor D. Wachs, R. Mac Thompson, C. Brooks Mobley, Carlton D. Fox, James R. McDonald, Brian S. Ferguson, Kaelin C. Young, Ben Nie, Jeffrey S. Martin, Joseph M. Company, David D. Pascoe, Robert D. Arnold, Jordan R. Moon, Michael D. Roberts. 2016. Ten weeks of branched-chain amino acid supplementation improves select performance and immunological variables in trained cyclists. Amino Acids, March 2016:vol. 48:no. 3:pp 779-789
Publisher
Springer Vienna
License
Journal
Volume
Issue
PubMed ID
DOI
ISSN
0939-4451
EISSN