Built
12-20-2006, 09:52 PM
Got a weird one I posted up on a few other boards.
While I understand the stuff's pretty much useless when it comes to muscle gain, I'm wondering if we may have been barking up the wrong tree - could it be useful for fat loss during cardio?
Anybody know anything about L-Arginine and cardio? From what I've read, it does a few things that might work in concert with caffeine/Yohimbine (ie peripheral blood supply to subcutaneous adipose tissue, catecholamine release) for something like HIIT and/or stubborn fat loss.
It has been shown to get fat off obese Zucker rats <rolls eyes>, and also off obese type-II diabetics as I recall … and a dosing of 6g L-arginine with 6mg yohimbine is well tolerated for ED (fellas, maybe rub one out BEFORE that AM HIIT session!)
Some possibly relevant links:
L-arginine and insulin sensitivity Beneficial effects of a long-term oral L-arginine treatment added to a hypocaloric diet and exercise training program in obese, insulin-resistant type 2 diabetic patients. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=16772327)
Long-term oral L-arginine administration improves peripheral and hepatic insulin sensitivity in type 2 diabetic patients. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=11347747)
"3g 3x per day"
Arginine increases catecholamines at rest Effects of L-arginine supplementation on exercise metabolism. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17143054&query_hl=123&itool=pubmed_docsum)
Dietary L-arginine supplementation reduces fat mass in Zucker diabetic fatty rats. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=15795423&query_hl=5&itool=pubmed_docsum)
Efficacy and safety of a novel combination of L-arginine glutamate and yohimbine hydrochloride: a new oral therapy for erectile dysfunction. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=12074777&query_hl=7&itool=pubmed_docsum)
From Effects of L-arginine supplementation on exercise metabolism (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17143054&query_hl=2&itool=pubmed_docsum)
"L-arginine infusion at rest increases plasma insulin, growth hormone, glucagon, catecholamines and prolactin. Such hormonal changes affect metabolism. There has, however, been very little examination of the effect of increases in L-arginine availability during exercise. This is important to study as there is preliminary evidence that L-arginine infusion, probably via increases in nitric oxide (NO), alters skeletal-muscle metabolism during exercise. "
Sadly, the research is rather thin in this regard. What I'm mostly looking for is a reason NOT to try this.
Oral bioavailability appears to be in the range of 68+/-9 (51-87)% for a 6g dose of oral L-arginine:
L-arginine-induced vasodilation in healthy humans: pharmacokinetic-pharmacodynamic relationship. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=9833603&query_hl=13&itool=pubmed_DocSum)
"Plasma L-arginine levels increased to (mean +/- s.e.mean) 6223+/-407 (range, 5100-7680) and 822+/-59 (527-955) micromol l(-1) after intravenous infusion of 30 g and 6 g L-arginine, respectively, and to 310+/-152 (118-1219) micromol l(-1) after oral ingestion of 6 g L-arginine. Oral bioavailability of L-arginine was 68+/-9 (51-87)%. Clearance was 544+/-24 (440-620), 894+/-164 (470-1190), and 1018+/-230 (710-2130) ml min(-1), and elimination half-life was calculated as 41.6+/-2.3 (34-55), 59.6+/-9.1 (24-98), and 79.5+/-9.3 (50-121) min, respectively, for 30 g i.v., 6 g i.v., and 6 g p.o. of L-arginine. Blood pressure and total peripheral resistance were significantly decreased after intravenous infusion of 30 g L-arginine by 4.4+/-1.4% and 10.4+/-3.6%, respectively, but were not significantly changed after oral or intravenous administration of 6 g L-arginine. L-arginine (30 g) also significantly increased urinary nitrate and cyclic GMP excretion rates by 97+/-28 and 66+/-20%, respectively. After infusion of 6 g L-arginine, urinary nitrate excretion also significantly increased, (nitrate by 47+/-12% [P<0.05], cyclic GMP by 67+/-47% [P= ns]), although to a lesser and more variable extent than after 30 g of L-arginine. The onset and the duration of the vasodilator effect of L-arginine and its effects on endogenous NO production closely corresponded to the plasma concentration half-life of L-arginine, as indicated by an equilibration half-life of 6+/-2 (3.7-8.4) min between plasma concentration and effect in pharmacokinetic-pharmacodynamic analysis, and the lack of hysteresis in the plasma concentration-versus-effect plot. CONCLUSIONS: The vascular effects of L-arginine are closely correlated with its plasma concentrations. These data may provide a basis for the utilization of L-arginine in cardiovascular diseases."
Thoughts?
While I understand the stuff's pretty much useless when it comes to muscle gain, I'm wondering if we may have been barking up the wrong tree - could it be useful for fat loss during cardio?
Anybody know anything about L-Arginine and cardio? From what I've read, it does a few things that might work in concert with caffeine/Yohimbine (ie peripheral blood supply to subcutaneous adipose tissue, catecholamine release) for something like HIIT and/or stubborn fat loss.
It has been shown to get fat off obese Zucker rats <rolls eyes>, and also off obese type-II diabetics as I recall … and a dosing of 6g L-arginine with 6mg yohimbine is well tolerated for ED (fellas, maybe rub one out BEFORE that AM HIIT session!)
Some possibly relevant links:
L-arginine and insulin sensitivity Beneficial effects of a long-term oral L-arginine treatment added to a hypocaloric diet and exercise training program in obese, insulin-resistant type 2 diabetic patients. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=16772327)
Long-term oral L-arginine administration improves peripheral and hepatic insulin sensitivity in type 2 diabetic patients. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=11347747)
"3g 3x per day"
Arginine increases catecholamines at rest Effects of L-arginine supplementation on exercise metabolism. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17143054&query_hl=123&itool=pubmed_docsum)
Dietary L-arginine supplementation reduces fat mass in Zucker diabetic fatty rats. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=15795423&query_hl=5&itool=pubmed_docsum)
Efficacy and safety of a novel combination of L-arginine glutamate and yohimbine hydrochloride: a new oral therapy for erectile dysfunction. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=12074777&query_hl=7&itool=pubmed_docsum)
From Effects of L-arginine supplementation on exercise metabolism (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17143054&query_hl=2&itool=pubmed_docsum)
"L-arginine infusion at rest increases plasma insulin, growth hormone, glucagon, catecholamines and prolactin. Such hormonal changes affect metabolism. There has, however, been very little examination of the effect of increases in L-arginine availability during exercise. This is important to study as there is preliminary evidence that L-arginine infusion, probably via increases in nitric oxide (NO), alters skeletal-muscle metabolism during exercise. "
Sadly, the research is rather thin in this regard. What I'm mostly looking for is a reason NOT to try this.
Oral bioavailability appears to be in the range of 68+/-9 (51-87)% for a 6g dose of oral L-arginine:
L-arginine-induced vasodilation in healthy humans: pharmacokinetic-pharmacodynamic relationship. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=9833603&query_hl=13&itool=pubmed_DocSum)
"Plasma L-arginine levels increased to (mean +/- s.e.mean) 6223+/-407 (range, 5100-7680) and 822+/-59 (527-955) micromol l(-1) after intravenous infusion of 30 g and 6 g L-arginine, respectively, and to 310+/-152 (118-1219) micromol l(-1) after oral ingestion of 6 g L-arginine. Oral bioavailability of L-arginine was 68+/-9 (51-87)%. Clearance was 544+/-24 (440-620), 894+/-164 (470-1190), and 1018+/-230 (710-2130) ml min(-1), and elimination half-life was calculated as 41.6+/-2.3 (34-55), 59.6+/-9.1 (24-98), and 79.5+/-9.3 (50-121) min, respectively, for 30 g i.v., 6 g i.v., and 6 g p.o. of L-arginine. Blood pressure and total peripheral resistance were significantly decreased after intravenous infusion of 30 g L-arginine by 4.4+/-1.4% and 10.4+/-3.6%, respectively, but were not significantly changed after oral or intravenous administration of 6 g L-arginine. L-arginine (30 g) also significantly increased urinary nitrate and cyclic GMP excretion rates by 97+/-28 and 66+/-20%, respectively. After infusion of 6 g L-arginine, urinary nitrate excretion also significantly increased, (nitrate by 47+/-12% [P<0.05], cyclic GMP by 67+/-47% [P= ns]), although to a lesser and more variable extent than after 30 g of L-arginine. The onset and the duration of the vasodilator effect of L-arginine and its effects on endogenous NO production closely corresponded to the plasma concentration half-life of L-arginine, as indicated by an equilibration half-life of 6+/-2 (3.7-8.4) min between plasma concentration and effect in pharmacokinetic-pharmacodynamic analysis, and the lack of hysteresis in the plasma concentration-versus-effect plot. CONCLUSIONS: The vascular effects of L-arginine are closely correlated with its plasma concentrations. These data may provide a basis for the utilization of L-arginine in cardiovascular diseases."
Thoughts?