Effect of acute L-arginine supplementation on 20 km time trial performance in competitive male cyclists

Abstract

Increasing literature has studied the effects of dietary nitrates and moreover, L-arginine supplementation on tolerance to exercise and O(2) consumption during exercise. However, few studies have investigated the effects of L-arginine on performance measures such as a time trial. It was hypothesised that an acute 3-day L-arginine supplementation would elicit a significant improvement in performance and reduce oxygen consumption during a 20 km time trial. 6 healthy male competitive cyclists (23 ± 5 y) participated in a double-blind crossover study, and consumed either one 500 m placebo (PLA) or L-arginine (ARG) beverage, containing 6 g of L-arginine, over a 2 week testing period. Following a 3-day supplementation, participants completed a ramped incremental test to exhaustion, followed by an hours rest and subsequently a 20 km time trial. Time trial completion time was reduced by 34 s (PLA 32:38 ± 1:50 vs ARG 32:04 ± 1:38 min, P<0.05), O(2) consumption during the time trial was also reduced (PLA 51.6 ± 8.2 vs ARG 47.5 ± 6.1 mL(.)kg(.)min(-1), P<0.05). Furthermore, both systolic and diastolic blood pressure were greatly reduced (PLA 132 ± 7 vs ARG 127 ± 7 mm Hg P<0.05 and PLA 79 ± 5 vs ARG 74 ± 5 mm Hg respectively, P<0.05). However, no differences were seen in participants' VO(2)max during the ramped incremental test to exhaustion (58 ± 8 vs 58 ± 8 ml(.)kg(.)min(-1), P>0.05) although W(peak) was higher during the same test (PLA 385 ± 38 vs ARG 395 ± 39 W). In conclusion, acute 3-day L-arginine supplementation at a dose of 6 g(.)day(-1) increases 20 km time trial performance and reduces O(2) consumption during time trial performance, in addition to reducing systolic and diastolic blood pressure. However, L-arginine appears to have no effect upon VO(2)max.

Full text

ISSSMC abstracts
Br J Sports Med 2011;45:e5. doi:10.1136/bjsports-2011-090606 A11
35 EFFECT OF ACUTE L-ARGININE SUPPLEMENTATION ON 20
KM TIME TRIAL PERFORMANCE IN COMPETITIVE MALE
CYCLISTS
M K Ranchordas, T Whitehead Department of Sport, Faculty of Health & Wellbeing,
Sheffield Hallam University, Sheffield, UK
10.1136/bjsports-2011-090606.35
Increasing literature has studied the effects of dietary nitrates
and moreover, L-arginine supplementation on tolerance to
exercise and O2 consumption during exercise. However, few
studies have investigated the effects of L-arginine on per-
formance measures such as a time trial. It was hypothesised
that an acute 3-day L-arginine supplementation would elicit
a signifi cant improvement in performance and reduce oxygen
consumption during a 20 km time trial. 6 healthy male com-
petitive cyclists (23 ± 5 y) participated in a double-blind cross-
over study, and consumed either one 500 m placebo (PLA) or
L-arginine (ARG) beverage, containing 6 g of L-argin ine, over
a 2 week testing period. Following a 3-day supplementation,
participants completed a ramped incremental test to exhaus-
tion, followed by an hours rest and subsequently a 20 km time
trial. Time trial completion time was reduced by 34 s (PLA
32:38 ± 1:50 vs A RG 32:04 ± 1:38 min, P<0.05), O2 consump-
tion during the time trial was also reduced (PLA 51.6 ± 8.2 vs
ARG 47.5 ± 6.1 mL.kg.min-1, P<0.05). Furthermore, both sys-
tolic and diastolic blood pressure were greatly reduced (PLA
132 ± 7 vs ARG 127 ± 7 mm Hg P<0.05 and PLA 79 ± 5 vs ARG
74 ± 5 mm Hg respectively, P<0.05). However, no differences
were seen in participants’ VO2max during the ramped incre-
mental test to exhaustion (58 ± 8 vs 58 ± 8 ml.kg.min-1, P>0.05)
although Wpeak was higher during the same test (PLA 385 ±
38 vs ARG 395 ± 39 W). In conclusion, acute 3-day L-argin ine
supplementation at a dose of 6 g.day-1 increases 20 km time
trial performance and reduces O2 consumption during time
trial performance, in addition to reducing systolic and dia-
stolic blood pressure. However, L-arginine appears to have no
effect upon VO2max
epage-bjsports-2011-090606.indd Sec1:11epage-bjsports-2011-090606.indd Sec1:11 10/29/2011 5:21:30 PM10/29/2011 5:21:30 PM
group.bmj.com on November 1, 2012 - Published by bjsm.bmj.comDownloaded from

doi: 10.1136/bjsports-2011-090606.35
2011 45: A11Br J Sports Med
M K Ranchordas and T Whitehead
competitive male cyclists
on 20 km time trial performance in
Effect of acute L-arginine supplementation
http://bjsm.bmj.com/content/45/15/A11.2
Updated information and services can be found at:
These include:
service
Email alerting the box at the top right corner of the online article.
Receive free email alerts when new articles cite this article. Sign up in
Collections
Topic
(83 articles)Cycling 
Articles on similar topics can be found in the following collections
Notes
http://group.bmj.com/group/rights-licensing/permissions
To request permissions go to:
http://journals.bmj.com/cgi/reprintform
To order reprints go to:
http://group.bmj.com/subscribe/
To subscribe to BMJ go to:
group.bmj.com on November 1, 2012 - Published by bjsm.bmj.comDownloaded from