POSTER PRESENTATION Open Access
Ten weeks of branched chain amino acid
supplementation improves select performance
and immunological variables in trained cyclists
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
From The Twelfth International Society of Sports Nutrition (ISSN) Conference and Expo
Austin, TX, USA. 11-13 June 2015
We examined if supplementing trained cyclists (32 ± 2 yr,
77.8 ± 2.6 kg, and 7.4 ± 1.2 yr training) with 12g/d (6g/d
L-Leucine, 2g/d L-Isoleucine and 4g/d L-Valine) of either
branched chain amino acids (BCAAs, n = 9) or a malto-
dextrin placebo (PLA, n = 9) over a 10-week training sea-
son affected select body composition, performance,
and/or immune variables.
Before and after the 10-week study, the following was
assessed: a) 4-h fasting blood draws; b) dual X-ray
absorptiometry body composition; c) Wingate peak
power tests; and d) 4km 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). 4km 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 perfor-
mance 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.
School of Kinesiology, Auburn University, Auburn, AL, USA.
College of Osteopathic Medicine, Auburn Campus, Auburn, AL, USA.
Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.
Endurance Company, LLC, Bloomington, IL, USA.
Science Institute, Denver, CO, USA.
Published: 21 September 2015
Cite this article as: Kephart et al.: Ten weeks of branched chain amino
acid supplementation improves select performance and immunological
variables in trained cyclists. Journal of the International Society of Sports
Nutrition 2015 12(Suppl 1):P20.
* Correspondence: firstname.lastname@example.org
School of Kinesiology, Auburn University, Auburn, AL, USA
Full list of author information is available at the end of the article
Kephart et al.Journal of the International Society of Sports Nutrition 2015, 12(Suppl 1):P20
© 2015 Kephart et al. This is an Open Access artic le distributed under the terms of the Creative Commons Attribution License (http://
creativecommons.org/licenses/by/4.0), which permits unr estricted use, distribution, and reproduction in any medium, provided the
original work is properly cited. The Cre ative Commons Public Do main Dedication waiver (http://creativecommons.org/publicdomain/
zero/1.0/) applies to the data made availa ble in this article, unless otherwise stated.