Posts : 1279
Join date : 2009-07-26
Age : 50
Location : UK
|Subject: L-arginine supplementation in young active males does not appear to work Sun Nov 27, 2011 4:22 am|| |
Sorry lads, no NO2 boost, no GH improvement, no IGF-1 increase. The only effect is increased levels of arginine in the blood, so it would appear that the main group of people wanting the supplement (young males) are actually getting zero benefit from it.
Put the abstract below:
- Quote :
Appl Physiol Nutr Metab. 2011 Jun;36(3):405-11. Epub 2011 May 16.
The acute effects of a low and high dose of oral L-arginine supplementation in young active males at rest.
Forbes SC, Bell GJ.
Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada. email@example.com
L-arginine (2-amino-5-guanidinovaleric acid) is a conditionally essential amino acid. Intravenous (IV) administration of l-arginine invokes a large metabolic (nitrate/nitrite (NO(x))) and hormonal (growth hormone (GH), insulin-like growth factor 1 (IGF-1), and insulin) response; however, research examining oral l-arginine supplementation is conflicting, potentially owing to dose. The purpose of this study was examine a low and high dose of oral l-arginine on blood l-arginine, NO(x), GH, IGF-1, and insulin response. Fourteen physically active males (age: 25 ± 5 years; weight: 78.0 ± 8.5 kg; height: 179.4 ± 4.7 cm) volunteered to be in a randomized, double-blind, repeated-measures study. Following an overnight fast, an IV catheter was placed in a forearm vein and a resting blood sample was drawn at ∼0800 hours. Each subject was then provided 1 of 3 treatment conditions (placebo, low (0.075 g·kg(-1) of body mass), or high (0.15 g·kg(-1) of body mass of l-arginine)). Blood samples were drawn at 30, 60, 90, 120, and 180 min after consumption. l-arginine plasma concentrations significantly increased (p < 0.001) to a similar level at any time point in both the low- and high-dose conditions; there was no change over time in the placebo condition. There was no significant difference between conditions for NO(x), GH, IGF-1, or insulin. Based on these findings, a low dose of l-arginine was just as effective at increasing plasma l-arginine concentrations as a high dose; however, neither dose was able to promote a significant increase in NO(x), GH, IGF-1, or insulin at rest.