Arginina ...

[Eagle]

Non fatemene una colpa, cerco studi a tempo perso, per avere conferme sugli integratori ... e trovo sempre studi che me li distruggono ...

Int J Sports Med. 2005 Jun;26(5):344-9. Links
Influence of chronic supplementation of arginine aspartate in endurance athletes on performance and substrate metabolism - a randomized, double-blind, placebo-controlled study.

Abel T, Knechtle B, Perret C, Eser P, von Arx P, Knecht H.
Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil.
The intake of arginine aspartate has been shown to increase anabolic hormones like human growth hormone (hGH) and glucagon. The aim of our study was to investigate whether daily intake of two different dosages of arginine asparate during four weeks affects selected parameters of overtraining syndrome like performance, metabolic and endocrine parameters. Thirty male endurance-trained athletes were included in a randomized, double-blind, placebo-controlled study and divided into three groups. During four weeks, they ingested either arginine aspartate with a high concentration (H) of 5.7 g arginine and 8.7 g aspartate, with a low concentration (L) of 2.8 g arginine and 2.2 g aspartate or placebo (P).VO(2)peak and time to exhaustion were determined on a cycling ergometer in an incremental exercise test before and after supplementation. Before and after each incremental exercise test, concentrations of hGH, glucagon, testosterone, cortisol, ferritine, lactate, and urea were measured. Compared to placebo, no significant differences on endurance performance (VO(2)peak, time to exhaustion), endocrine (concentration of hGH, glucagon, cortisol, and testosterone) and metabolic parameters (concentration of lactate, ferritine, and urea) were found after chronic arginine aspartate supplementation. The chronic intake of arginine asparate during four weeks by male endurance athletes showed independent of dosage no influence on performance, selected metabolic or endocrine parameters. Consequently, there seems to be no apparent reason why the supplementation of arginine aspartate should be an effective ergogenic aid. The practice of using arginine aspartate as potential ergogenics should be critically reevaluated. Further investigations with higher dosage and extended supplementation periods should be performed.

[Eagle]

Qui' avrei qualche cosa da ridire sull'interpretazione dei risutlati ormonali ... ogni tanto i ricercatori sono un pochino poco "intuitivi" ... cosa mai vorra' dire se aumentano alcuni ormoni anabolici e si riducono gli aminoacidi nel sangue???

che gli aa vengono usati per costruire proteine ...

Eur J Nutr. 1999 Dec;38(6):263-70. Links
Chronic arginine aspartate supplementation in runners reduces total plasma amino acid level at rest and during a marathon run.

Colombani PC, Bitzi R, Frey-Rindova P, Frey W, Arnold M, Langhans W, Wenk C.
Swiss Federal Institute of Technology, Zurich. paolo.colombani@inw.agrl.ethz.ch
BACKGROUND: Athletes consume arginine and/or aspartate as potential nutritional ergogenics. Their metabolic effects are controversial and there is some evidence that ingestion of large doses of single amino acids can adversely affect the nitrogen balance or induce an amino acid imbalance. Nevertheless, the general metabolic influence of an arginine aspartate supplementation during a prolonged exercise bout has not yet been investigated. AIM OF THE STUDY: The aim of this study was, therefore, to investigate the general metabolic impact of a chronic supplementation with arginine aspartate in endurance-trained athletes at rest and during a marathon run. METHODS: Fourteen endurance-trained runners participated in this field study which was carried out according to a double-blind crossover design. 15 g of arginine aspartate or a carbohydrate-based placebo were supplemented daily for 14 days before a marathon run. Blood samples for analysis of metabolites and hormones were collected shortly before the run, after 31 km, at the end of the run, and after a recovery period of two hours. Additionally, the respiratory exchange ratio was determined during the run. RESULTS: The plasma level of carbohydrate (glucose, lactate, pyruvate) and fat metabolites (fatty acids, glycerol, beta-hydroxybutyrate), cortisol, insulin, ammonia, lactate dehydrogenase, and creatine kinase as well as the respiratory exchange ratio were unaffected by the supplementation. In contrast, the plasma level of somatotropic hormone, glucagon, urea, and arginine were significantly increased, and the level of most of the remaining plasma amino acids as well as their sum was significantly reduced. CONCLUSIONS: There was no obvious metabolic benefit derived from the chronic supplementation with arginine aspartate. And since furthermore the consequences of a reduction of the total plasma amino acid level are not known, the practice of using single amino acid supplements as potential ergogenics should be critically reevaluated.

[Eagle]

con la lisina ha ridotto l'ansia e i valori di alcuni ormoni da stress (incluso il cortisolo) ... boh ... che significato potrebbe avere per il bber? (domanda ovviamente retorica, se non si fa uno studio non lo sapremo mai...)

Biomed Res. 2007 Apr;28(2):85-90. Links
Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans.

Smriga M, Ando T, Akutsu M, Furukawa Y, Miwa K, Morinaga Y.
Institute of Life Sciences, Ajimoto Co. Inc, 1-1 Suzuki-cho, 210-8681 Kawasaki-ku, Kawasaki-shi, Japan. miro_smriga@ehq.ajinomoto.com
Dietary supplementation with an essential amino acid L-lysine has been shown to reduce chronic anxiety in humans with low dietary intake of L-lysine. A combination of L-lysine and L-arginine has been documented to normalize hormonal stress responses in humans with high trait anxiety. The present study was carried out in one hundred eight healthy Japanese adults. The aim of study was to find out whether a week-long oral treatment with L-lysine (2.64 g per day) and L-arginine (2.64 g per day) reduces trait and stress-induced state anxiety and basal levels of stress hormones. We confirmed that, without regard to gender, the amino acid treatment significantly reduced both trait anxiety and state anxiety induced by cognitive stress battery. In addition, we found that the treatment with L-lysine and L-arginine decreased the basal levels of salivary cortisol and chromogranin-A (a salivary marker of the sympatho-adrenal system) in male subjects. These results of this double-blind, placebo controlled and randomized study confirm the previous findings in humans and animals and point to a combination of L-lysine and L-arginine as a potentially useful dietary intervention in otherwise healthy humans with high subjective levels of mental stress and anxiety.

[master wallace]

I reali effetti che rilevo con l'arginina sono un maggior pump ed erezioni.

[Eagle]

questo non e' male, non conclude niente, e' solo un insieme di riflessioni ... pero' ... meglio di niente.

Curr Opin Clin Nutr Metab Care. 2007 Jan;10(1):46-51. Links
Effects of L-arginine supplementation on exercise metabolism.

McConell GK.
Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia. mcconell@unimelb.edu.au
PURPOSE OF REVIEW: To describe the influence of acute and chronic administration of L-arginine on metabolism at rest and during exercise. RECENT FINDINGS: There has been substantial examination of the effect of infusion and ingestion of L-arginine at rest. It has been clearly demonstrated that L-arginine administration improves endothelial function in various disease states. In addition, 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. There is a need for further research, especially to understand the mechanisms of how L-arginine affects exercise metabolism and also to determine whether the hormonal responses that occur in response to L-arginine at rest are also present to some extent during exercise. SUMMARY: This line of research may have important therapeutic implications as there are indications that L-arginine augments the effects of exercise training on insulin sensitivity and capillary growth in muscles.

[bloodz]

I reali effetti che rilevo con l'arginina sono un maggior pump ed erezioni.

idem...muscolo sempre pieno anche nei giorni di off e aumento della libido.