jao taj Glutamin,
verovali ili ne, najveca prevara.
Znaci lik kome je ti posao, tj. nauka kojom se bavi proucava telo i njegove realcije na vezbanje, prehranu i suplementaciju mi je to potvrdio.
Nema ni jednog, ali ni jednog dokaza da glutamin pomaze oporavku ili napretku u masi.
Znam, ne mozete da poverujete !
evo jedne studije (a ima ih mnogo vise):
Glutamine is a non-essential amino acid, that is, the human body can synthesize the amino acid and it is not required through the diet. Glutamate is produced when an amino group is added to keto-acids. In turn keto-acids are formed by transamination (removal of amino group) of amino acids. Glutamine is formed when an amino group is added to glutamate by the enzyme glutamine synthetase. Glutamine/glutamate is found in great concentration in muscle tissue, gut tissue and blood circulation.
There are many studies on critically ill patients and supplemental glutamine. Those studies have shown maintenance of muscle mass and improved immune sytem. There are several studies that have also shown good effect on the gut.
The topic for this article is though, to see if glutamine supplementation has a positive effect on body composition in healthy adults. There are several claims that glutamine "works like creatine" in that it increases intracellular volume of muscle cells. The hypothesis is that glutamine promotes increases in cellular volume and osmolarity as a result of an insulin and sodium dependent transport system. That increased cellular swelling is suggested to start an anabolic proliferative signal and the muscle cell will grow (ref. 1, 5, 6). Tarnopolsky et al have shown many years ago, that glutamine supplementation may have an effect on muscle protein levels (ref. . Others also claims it improves immune system in healthy adults.
Candow (ref. 3) et al studied glutamine supplementation in resistance training young adults. 31 subjects were divided in 2 groups. One group recieved glutamine ( 0.9 g / kg lean tissue mass) and the other group recieved maltodextrin ( 0.9 g / kg lean tissue mass). Before and after, 1 repetition maximum (1 RM) of squats, bench press and peak knee extension were measured. Measurements of lean tissue mass and urinary measurements of muscle degradation were also made. The strength training program consisted for 6 weeks. The study showed that strength training increased (of course) strength and lean tissue mass. The study could not show any differences between the groups. That means that glutamine supplementation failed to show any additional effects on strength and lean body mass in this study.
The second study by Lehmkuhl et al (ref. 6) is a study where creatine and glutamine supplementation is evaluated. In this study, there were 29 track and field athletes who did the same strength and conditioning program. They were divided into 3 groups. One group received creatine monohydrate (CM), one group received creatine monohydrate and glutamine ( 4 g daily) and the third group recieved placebo (potato starch). The study was for 8 weeks. The study showed a greater increase in lean body mass in the creatine and creatine/glutamine groups compared with placebo. No differences between the creatine and creatine/glutamine groups were observed. This study might suggest a positive effect with creatine supplementation but no clear evidence that glutamine has a postitive effect.
Another study, in which effervescent creatine, ribose and glutamine supplementation was compared with placebo (simple sugar), failed to show an effect of the supplementation (ref. 4)
Antonio et al (ref. 2) suggested that long-term ingestion of glutamine may have positive effects on muscular strength although their study did not show any effect of glutamine. In this study 6 resistance training men performed weightlifting exercises after ingestion of glutamine or glycine mixed with calorie-free fruit juice or placebo (calorie-free fruit juice only). The study did not show any effect of glutamine. The study was of short term.
In an article by Rohde et al (ref. 7), interesting links between glutamine, training and immune system are presented. The study showed that exercise (bicycle) decreased glutamine and lymphocytes (could be a mechanism in which hard training can cause increased frequency of infections). Supplemental glutamine did not have an effect on this fact.
Conclusion
No one can argue that glutamine has an anti-catabolic/anabolic effect in critically ill patients.
In healthy, weight training athletes glutamine supplementation has failed to show any effect on lean body mass or strength. The studies are small and few and usually of fairly short term. More studies are needed to explore glutamine as an anabolic signal. It would be interesting to study the effect of glutamine in severe training (border to overtraining), I have a feeling that in that kind of study glutamine might have an effect (considering the results in critically ill patients). Many athletes report good effect of glutamine but when it is studied in scientific way, it fails to show an effect. Thus, glutamine cannot be recommended as an agent to increase lean body mass at this moment.
References:
Antonio J et al, Glutamine: A potentially useful supplement for athletes, Can J Appl Physiol 24:1-14, 1999.
Antonio J et al, The effects of high-dose glutamine ingestion on weightlifting performance, J Strength Cond Res 16:157-160, 2002.
Candow LM et al, Effect of glutamine supplementation combined with resistance training in young adults, Eur J Appl Physiol 86:142-149, 2001.
Darin J et al, Effects of effervescent creatine, ribose, and glutamine supplementation on muscular strength, muscular endurance and body composition, J Strength Cond Res 17(4):810-816, 2003.
Haussinger D et al, Cellular hydration state: An important determinant of protein catabolism in health and disease, Lancet 341:1330-1332, 1993.
Lehmkuhl M et al, The effects of 8 weeks of creatine monohydrate and glutamine supplementation on body composition and performance measures, J Strength Cond Res 17(3):425-438, 2003.
Rohde T et al, Effect of glutamine supplementation on changes in the immune system induced by repeated exercise, Med Sci Sports Exerc 30:856-862, 1998.
Tarnopolsky MA et al, Influence of protein intake and training status on nitrogen balance and lean body mass, J Appl Physiol 64:187-193, 1988.
About the writer: Carl-Marcus Lokrantz, MD and nutritionist, studied medicine at the prestigous Karolinska Institute, Stockholm, Sweden and also studied Nutrition at Stockholm University. Carl-Marcus Lokrantz works in internal medicine and also has a buisiness where he helps bodybuilders with training, nutrition and managing. His company LOKRANTZ CONSULTING offers the complete support for the serious athlete. For more information, check out
www.lokrantzconsulting.com.
I jos jedna:
http://healthlibrary.epnet.com/GetContent.aspx?token=e0498803-7f62-4563-8d47-5fe33da65dd4&chunkiid=21749I na kraju, glutamin je skup i vrlo je tesko izvrsiti istrazivanje koje bi trajalo npr 1 godinu sa min 30 ispitanika.
Ovako, nikad necemo znati da li "stvarno" radi ili ne!
I zapamtite, PLACEBO efekat je neverovatan.
manje od 5% suplemenata na trzistu stvarno deluje !
Poz
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