xtend is pretty good. although the good feeling i get from it, i believe is mainly because of the citrulline malate <-- awesome amino acid TBH. 3grams CM before a session keeps me feeling good for 2 intense hours
citrulline malate is the real deal.
i usually buy it alone in 500 gram small tubs from a longtime reputable source - ZERO fillers.
i had read 7-8 years ago that adding 1 gram of L-citrulline to 4-6 grams L-arginine was the ideal formula from Dr. Ignarro's book "NO More heart Disease:
"Dr. Louis Ignarro discovered "the atom" of cardiovascular health--a tiny molecule called Nitric Oxide. NO, as it is known by chemists, is a signaling molecule produced by the body, and is a vasodilator that helps control blood flow to every part of the body. Dr. Ignarro's findings led to the development of Viagra. Nitric Oxide has a beneficial effect on the cardiovascular system as well." (note:sadly Dr. Ignarro never benefited financially from any of the ED meds such as viagra, etc... others took his research and ran with it)
... newer studies have shown 3-6 grams of citrulline malate converts much better into L-Arginine creating the vasodilation-widening of blood vessels.
when blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance. dilation of arterial blood vessels mainly the arterioles
decreases blood pressure and allows more OXYGEN rich blood to flow throughout body.
3-6 grams citrulline malate works by powering ATP - the energy molecule that fuels muscle production and eliminates toxins such as lactic acid and also ammonia from the blood.
i use it every deadlift and squat workout - and yes i can go for about two hours of heavy duty lifting as opposed to running out of steam after about 50-60 minutes.
...i am not a rep for any company but play one on TV. i can be seen in old westerns riding my Medicine Man Show wagon into the town of North Fork promoting generic citrulline malate.
[ame="http://www.amazon.com/dp/0312335822/?tag=googhydr-20&hvadid=35261900641&hvpos=1t3&hvexid=&hvnetw=g&hvrand=18292107151230699588&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_19vegdiitt_b"]NO More Heart Disease: How Nitric Oxide Can Prevent--Even Reverse--Heart Disease and Strokes: Louis Ignarro: 9780312335823: Amazon.com: Books[/ame]
This post for entertainment purposes only and not meant to diagnose or treat any medical issues.