Cutting supplements

[StoneGRMI]

I just finished up a bulk and I didn't do it as clean as I should have and am learning the hard way (packed on a little too much fat). I'm starting a very strick cutting diet now. Ive started taking a ephedra stack but instead of caffeine I'm using green tea extract. I'm doing this because caffeine makes me too hyper, is green tea a good thing to substitute the caffeine in the stack? Each serving has 300mg green tea leaf extract and 150mg polyphenols, how much do I need? Also are there any other supplements worth while for cutting? L-carntine? Thanks guys.

[Giantz11]

get acetyl-l-carnitine far more effective andgreen tea should be fine.

[nsa]

I just finished up a bulk and I didn't do it as clean as I should have and am learning the hard way (packed on a little too much fat). I'm starting a very strick cutting diet now. Ive started taking a ephedra stack but instead of caffeine I'm using green tea extract. I'm doing this because caffeine makes me too hyper, is green tea a good thing to substitute the caffeine in the stack? Each serving has 300mg green tea leaf extract and 150mg polyphenols, how much do I need? Also are there any other supplements worth while for cutting? L-carntine? Thanks guys.

I actually prefer Green Tea over Caffeine. I use alot more Gree Tea Extract though, like 1-2g each day. If you wanted to add to that i would add Acetyl-L-Carnitine instead of L-Carnitine.

[StoneGRMI]

Okay cool, I'll up the green tea. As for the L-Carnitine and acetyl L-Carnitine, whats the difference? I only say that because I just picked up some L-Carnitine for real cheap but havent cracked the seals on it yet.

[StoneGRMI]

Anyone know the difference between L-Carnitine and acetyl L-Carnitine? Just want to know if its worth returning the L-Carnitine I already bought. Thanks!

[prolangtum]

from an article by david tolson on 1 f ast400.com:

"What form is best?

Pharmacologically speaking, there is little difference between supplementing with L-carnitine and supplementing with ALCAR. This is because ALCAR is deacetylated during or immediately after intestinal cell uptake, and then a certain amount of free carnitine is later reacetylated (1, 2). Similarly, it has been shown that supplementation with both L-carnitine and ALCAR increase tissue levels of both substances, and that the intestine creates significant amounts of ALCAR from carnitine (2, 3). "

[macrophage69alpha]

from an article by david tolson
"What form is best?

Pharmacologically speaking, there is little difference between supplementing with L-carnitine and supplementing with ALCAR. This is because ALCAR is deacetylated during or immediately after intestinal cell uptake, and then a certain amount of free carnitine is later reacetylated (1, 2). Similarly, it has been shown that supplementation with both L-carnitine and ALCAR increase tissue levels of both substances, and that the intestine creates significant amounts of ALCAR from carnitine (2, 3). "

this information is misleading and innaccurate. none of the studies cited (1,2,3) indicate what is being said. only relevant reference (2) studies carntine metabolism in isolated enterocytes. The article makes irrelevant and innacurate claims.

these claims are accurate.
Acetyl-l-carnitine sigificantly raises plasma acetyl-l-carnitine levels (see below)
acetyl-l-carnitine has significant effects not seen with carnitine supplementation. (see pubmed)
Ann N Y Acad Sci. 2004 Nov;1033:30-41. Related Articles, Links


Kinetics, pharmacokinetics, and regulation of L-carnitine and acetyl-L-carnitine metabolism.

Rebouche CJ.

Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA. [email protected]

In mammals, the carnitine pool consists of nonesterified L-carnitine and many acylcarnitine esters. Of these esters, acetyl-L-carnitine is quantitatively and functionally the most significant. Carnitine homeostasis is maintained by absorption from diet, a modest rate of synthesis, and efficient renal reabsorption. Dietary L-carnitine is absorbed by active and passive transfer across enterocyte membranes. Bioavailability of dietary L-carnitine is 54-87% and is dependent on the amount of L-carnitine in the meal. Absorption of L-carnitine dietary supplements (0.5-6 g) is primarily passive; bioavailability is 14-18% of dose. Unabsorbed L-carnitine is mostly degraded by microorganisms in the large intestine. Circulating L-carnitine is distributed to two kinetically defined compartments: one large and slow-turnover (presumably muscle), and another relatively small and rapid-turnover (presumably liver, kidney, and other tissues). At normal dietary L-carnitine intake, whole-body turnover time in humans is 38-119 h. In vitro experiments suggest that acetyl-L-carnitine is partially hydrolyzed in enterocytes during absorption. In vivo, circulating acetyl-L-carnitine concentration was increased 43% after oral acetyl-L-carnitine supplements of 2 g/day, indicating that acetyl-L-carnitine is absorbed at least partially without hydrolysis. After single-dose intravenous administration (0.5 g), acetyl-L-carnitine is rapidly, but not completely hydrolyzed, and acetyl-L-carnitine and L-carnitine concentrations return to baseline within 12 h. At normal circulating l-carnitine concentrations, renal l-carnitine reabsorption is highly efficient (90-99% of filtered load; clearance, 1-3 mL/min), but displays saturation kinetics. Thus, as circulating L-carnitine concentration increases (as after high-dose intravenous or oral administration of L-carnitine), efficiency of reabsorption decreases and clearance increases, resulting in rapid decline of circulating L-carnitine concentration to baseline. Elimination kinetics for acetyl-L-carnitine are similar to those for L-carnitine. There is evidence for renal tubular secretion of both L-carnitine and acetyl-L-carnitine. Future research should address the correlation of supplement dosage, changes and maintenance of tissue L-carnitine and acetyl-L-carnitine concentrations, and metabolic and functional changes and outcomes.

[nsa]

this information is misleading and innaccurate. none of the studies cited (1,2,3) indicate what is being said. only relevant reference (2) studies carntine metabolism in isolated enterocytes. The article makes irrelevant and innacurate claims.

these claims are accurate.
Acetyl-l-carnitine sigificantly raises plasma acetyl-l-carnitine levels (see below)
acetyl-l-carnitine has significant effects not seen with carnitine supplementation. (see pubmed)
Ann N Y Acad Sci. 2004 Nov;1033:30-41. Related Articles, Links


Kinetics, pharmacokinetics, and regulation of L-carnitine and acetyl-L-carnitine metabolism.

Rebouche CJ.

Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA. [email protected]

In mammals, the carnitine pool consists of nonesterified L-carnitine and many acylcarnitine esters. Of these esters, acetyl-L-carnitine is quantitatively and functionally the most significant. Carnitine homeostasis is maintained by absorption from diet, a modest rate of synthesis, and efficient renal reabsorption. Dietary L-carnitine is absorbed by active and passive transfer across enterocyte membranes. Bioavailability of dietary L-carnitine is 54-87% and is dependent on the amount of L-carnitine in the meal. Absorption of L-carnitine dietary supplements (0.5-6 g) is primarily passive; bioavailability is 14-18% of dose. Unabsorbed L-carnitine is mostly degraded by microorganisms in the large intestine. Circulating L-carnitine is distributed to two kinetically defined compartments: one large and slow-turnover (presumably muscle), and another relatively small and rapid-turnover (presumably liver, kidney, and other tissues). At normal dietary L-carnitine intake, whole-body turnover time in humans is 38-119 h. In vitro experiments suggest that acetyl-L-carnitine is partially hydrolyzed in enterocytes during absorption. In vivo, circulating acetyl-L-carnitine concentration was increased 43% after oral acetyl-L-carnitine supplements of 2 g/day, indicating that acetyl-L-carnitine is absorbed at least partially without hydrolysis. After single-dose intravenous administration (0.5 g), acetyl-L-carnitine is rapidly, but not completely hydrolyzed, and acetyl-L-carnitine and L-carnitine concentrations return to baseline within 12 h. At normal circulating l-carnitine concentrations, renal l-carnitine reabsorption is highly efficient (90-99% of filtered load; clearance, 1-3 mL/min), but displays saturation kinetics. Thus, as circulating L-carnitine concentration increases (as after high-dose intravenous or oral administration of L-carnitine), efficiency of reabsorption decreases and clearance increases, resulting in rapid decline of circulating L-carnitine concentration to baseline. Elimination kinetics for acetyl-L-carnitine are similar to those for L-carnitine. There is evidence for renal tubular secretion of both L-carnitine and acetyl-L-carnitine. Future research should address the correlation of supplement dosage, changes and maintenance of tissue L-carnitine and acetyl-L-carnitine concentrations, and metabolic and functional changes and outcomes.

Good stuff Macro...

[StoneGRMI]

Thanks a lot guys, helped a lot