Not so Fast Termy......
[From another member: HHajdo]
Here are two good articles about it:
Glutamine
Destroying the Dogma, Part 2
by David J. Barr
Last week, David Barr started shooting holes into the reputation of the long-standing bodybuilding supplement, glutamine.. While glutamine was staggered and bleeding at the end of part 1, watch as Barr sticks a sharp knife into glutamine's still barely beating heart and twists it.
Another One Bites the Dust
You may recall that the theory of exercise induced immunosuppression is often cited, based on the fact that glutamine levels decrease after exercise, as does our immunity.(10)
What we must now address is whether the relationship between the body’s glutamine stores and the effects of exercise on the immune system exhibit a causal or coincidental relationship (just as we did for protein synthesis). A recent review article in "The Journal of Applied Physiology" examined this connection between plasma glutamine and exercise-induced immunosuppression.(15)
The study admitted that there are conflicting reports about plasma glutamine levels following long duration exercise, repeated high intensity bouts, as well as short single high intensity bouts. This indicates that plasma glutamine concentrations may be affected differently depending on the intensity and duration of exercise.
Even data on blood glutamine concentrations following eccentric exercise is mixed, which can relate directly to bodybuilders and their use of heavy loads. Based on the relatively small reductions in plasma glutamine that might occur following exercise, supplementation with glutamine wouldn’t likely affect the immune cells.
More importantly, there are several studies showing that glutamine supplementation doesn't alter exercise-induced suppression of the immune system! The bottom line is that blood glutamine levels, whether they drop or not following exercise, don’t seem to affect immunity to any great extent, which precludes the use of glutamine for this reason.
Another recent review looked at over 75 research papers pertaining to the effect of glutamine on immunity and muscle growth, and came to the following conclusion: "Overall, although glutamine obviously plays important metabolic roles within the body, supplementation does not appear to provide consistent beneficial or therapeutic effects, except during certain catabolic situations. Glutamine availability, therefore, does not seem to be a limitation in many challenge situations."(19)
What about the glycogen?!
Yep, we have one final theory to validate spending God-awful amounts of money on glutamine; that of enhanced glycogen resynthesis following our workouts. In addition to the aforementioned studies showing better glycogen storage, there is also a study showing no effect of oral glutamine on glycogen regeneration following high intensity interval training.(26)
This issue was actually addressed by the authors of the Candow study, who found no strength or mass changes in trained individuals using glutamine (versus a placebo).(7) They suggested that the studies done showing enhanced glycogen recovery used exercise bouts which depleted intramuscular glycogen by 90%(!), while resistance exercise only depletes muscular glycogen by ~36%.
The bottom line is that the jury is still out on glutamine enhancing glycogen resynthesis following resistance exercise, but it seems unlikely that it would have any effect. Toss in the huge amounts of high glycemic carbs that most of us use following our workouts, and it’s almost a sure bet that glutamine won’t do anything for additional glycogen storage under normal dietary situations.
Things That Mom Never Told You About Glutamine Supplementation
It’s important to examine the method used for getting glutamine into the body in the human studies presented. Unfortunately, getting glutamine into our blood and to our muscles is a lot harder than one may expect. It was mentioned earlier that many cells of the body use glutamine for fuel. Well one area of cells that just loves glutamine is the gastrointestinal tract. In fact, it can account for up to 40% of glutamine utilization in the body! Now figure out the first area to come into contact with our "wonder supplement," and you can see that you have to take a whole crap-load of the stuff all at once, just so our gut doesn’t use it all!
Now, dumping 20g of one amino acid into our bodies at once may sound fun to some, but then again we can safely call these people masochists. For the rest of us, this huge glutamine dump may lead to some GI distress, which we all know is NOT fun.
Fortunately, the two studies performed with bodybuilders using relatively high dosages of glutamine (0.3g/kg/d and 0.9g/kg lean mass/d) reported no side effects of any kind.(2, 7) What is unfortunate is that the authors of these studies also showed no positive effect of any kind!
Glutamine and Resistance Trained Athletes: The Studies
One recent study examined the effect of acute glutamine ingestion on weightlifting performance.(2) This study examined the potential buffering effect of glutamine on lactic acid production during resistance exercise (to the point of momentary muscular failure).
One hour following glutamine ingestion (0.3g/kg), glycine ingestion (0.3g/kg), or placebo drink ingestion, the trained subjects performed 2 sets each of leg press (@ 200% body weight) and bench press (@ 100% body weight). This would equate to an average of ~23g of either amino acid ingested all at once, but there were no reports of GI discomfort.
Each subject consumed one of the three supplements before three separate testing sessions separated by a week. There was no effect of glutamine on number of reps performed compared to glycine or placebo ingestion. These results indicate that a high dose of glutamine ingested before exercise has no positive or negative effects on weightlifting performance in trained subjects.
If you’re interested in glutamine for its effect on muscle mass and strength, you’re in luck because a study was done on that, too! This next study is undoubtedly one of the best kept secrets in bodybuilding! In this study, the trained subjects consumed either 0.9g/kg lean body mass/day (average of 45g/day!), or a placebo, in 2 divided doses.(7)
It's noteworthy that using this amount of glutamine would run over 1200$USD per year for a 200lb guy!
By the end of the 6-week period, there were no differences in terms of 1Rep Max on squat or bench between the groups. There were also no differences between groups when it came to the gains in lean body mass (i.e. the amount of muscle they put on) during the trial period. This study was well designed and used the highest amount of glutamine ever studied for these purposes.
Glutamine Ain't All That Bad
After kicking the crap out of glutamine for most bodybuilding purposes, it is important to realize that there are certain situations where glutamine can be useful.
A recent study from the journal "Metabolism" shows that glutamine injections following glucocorticoid (ie catabolic steroid -such as cortisol) treatment can increase protein synthesis in the gastrointestinal system of dogs.(16) Unfortunately, nonoxidative leucine disposal, a measure of whole-body protein synthesis, remained unchanged in the glutamine treated group.
There are a dozen ways you could interpret these findings, but at least we can say that glutamine supplementation may improve protein synthesis in some tissues following gluccocorticoid treatment. In fact, glucocorticoid treatment is one area where glutamine supplementation may really help!
Another study with rats supports this contention, again using corticosteroid administration.(14) Although glutamine infusion had no effect on muscle protein synthesis in the rats not receiving cortisol, there was a beneficial effect in the glucocorticoid treated rats. In fact, glutamine infusion actually attenuated more than 70% of the muscle wasting caused by the cortisol injections!
Along these lines, certain catabolic conditions (such as sepsis) may be another useful situation in which glutamine could help out. One literature review clearly concluded that "The increased intake of glutamine has resulted in lower septic morbidity in certain critically ill patient populations."(3) This means that people with certain catabolic medical conditions may live longer when taking glutamine. Keeping this in mind, we also know that AIDS can be associated with muscle wasting. Recent evidence has arisen to demonstrate that glutamine supplementation may attenuate AIDS-induced muscle wasting.(25)
Overall, these studies show that glutamine could be very helpful for muscle mass during corticosteroid treatment and certain wasting conditions. For those of you who think that your everyday training may be intense enough to simulate a catabolic condition, keep in mind that these people are dying because of their catabolism, so you're really no where near that level.
The only time a bodybuilder even remotely approaches these kind of catabolic conditions is when improperly coming off a cycle of anabolic steroids. In this situation the user has minimal anabolic stimulus from Testosterone and a large amount of cortisol just waiting to eat that muscle (again, this is only when done improperly). In this situation, glutamine supplementation might help, but it's not a situation you should be in anyway.
The other time that glutamine supplementation may be beneficial to bodybuilders is when on a low carbohydrate diet. Glutamine can not only be converted to glucose, but may also have an anapleurotic effect.(5) In other words, it may replenish metabolic intermediates, in this case, ATP (especially important when you're lacking carbs). This is another article unto itself, so I'll leave it at that for now.
You may be asking why you’ve never heard of most of these studies, and why everything you’ve heard about glutamine was always so amazing. I can indirectly answer that by reminding you of one simple fact: no one makes money by showing that supplements don’t work. I’ll leave the rest of the thinking on this matter to you.
Despite this, you may still be skeptical regarding the points mentioned, based on the original dogmatic theories associated with glutamine use (and how long you’ve been hit over the head with them). But then again, that’s why they’re just theories. To paraphrase Homer Simpson: "Sure it may work in theory, but then again even communism works...in theory."
It's the mark of a great person who can devise a theory, drawing from many different ideas, and stick to it. Without this, science would be meaningless. But it's the mark of an even greater person when they can admit, without shame, that their idea is wrong.
Sometimes theories pan out and sometimes they don’t, but we have to be able to let go of them once they're shown to be incorrect. This doesn’t mean that we shouldn’t believe new theories when they first come out; it just means that we have to be conscious about the fact that they aren’t dogma and may be wrong.
Case in point: The theory behind glutamine was so great that I refused to believe the authors of the Candow et al. (2001) study when they told me the results in person. I was an educated bodybuilder and I wasn’t going to let some egghead scientist (who was actually more muscular than I was, and therefore far from being just an "egghead") tell me that I was wrong. Of course, I wanted to believe that glutamine was useful (even though I got nothing from it) and when someone wants to believe something you can’t convince them otherwise.
Since then I’ve had a while to let the results sink in. I know that most believers in glutamine will also have a hard time accepting the reality of the situation, which is why I didn’t just try to convincingly show that glutamine wasn’t as great as everyone thought; I tried to overwhelmingly demonstrate it.
Bottom Line
Glutamine is good for hospital patients and rich people with money to waste. If you’re involved in resistance training and already have proper post workout nutrition, along with a moderate carb intake, then glutamine probably won’t do anything for you. In fact, none of the proposed theories dealing with glutamine supplementation have worked out in the athletic world. It’s also one of the most expensive supplements around (simply based on dosage recommendations), so it’s way too costly to use for personal experimentation — especially when the updated scientific literature doesn’t support the theories.
David J. Barr, CSCS, MSc. Candidate, is a Varsity Strength and Conditioning Coach at the University of Waterloo. You can contact him at
[email protected].
References
1. Antonio J, Street C.
Glutamine: a potentially useful supplement for athletes. Can J Appl Physiol 1999 Feb;24(1):1-14
2. Antonio J, Sanders MS, Kalman D, Woodgate D, Street C.
The effects of high-dose glutamine ingestion on weightlifting performance. J Strength Cond Res 2002 Feb;16(1):157-60
3. Boelens PG, Nijveldt RJ, Houdijk AP, Meijer S, van Leeuwen PA.
Glutamine alimentation in catabolic state. J Nutr 2001 Sep;131(9 Suppl):2569S-77S; discussion 2590S
4. Bowtell JL, Gelly K, Jackman ML, Patel A, Simeoni M, Rennie MJ.
Effect of oral glutamine on whole body carbohydrate storage during recovery from exhaustive exercise. J Appl Physiol 1999 Jun;86(6):1770-7
5. Bruce M, Constantin-Teodosiu D, Greenhaff PL, Boobis LH, Williams C, Bowtell JL.
Glutamine supplementation promotes anaplerosis but not oxidative energy delivery in human skeletal muscle. Am J Physiol Endocrinol Metab 2001 Apr;280(4):E669-75
6. Bush JA, Dohi K, Mastro AM, Volek J, Lynch JM, Triplett-McBride, Putukian M, Sebastianelli WJ, Newton RU, Hakkinen K, Kraemer WJ. Exercise and recovery responses of lymphokines to heavy resistance exercise J Str Cond Res 2000 14(3) 344-349
7. Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T.
Effect of glutamine supplementation combined with resistance training in young adults. Eur J Appl Physiol 2001 Dec;86(2):142-9
8. Castell LM, Poortmans JR, Newsholme EA.
Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol Occup Physiol 1996;73(5):488-90
9. Castell LM, Newsholme EA.
The effects of oral glutamine supplementation on athletes after prolonged, exhaustive exercise. Nutrition 1997 Jul-Aug;13(7-8):738-42
10. Castell LM.
Can glutamine modify the apparent immunodepression observed after prolonged, exhaustive exercise? Nutrition 2002 May;18(5):371-5
11. Fang CH, James JH, Fischer JE, Hasselgren PO.
Is muscle protein turnover regulated by intracellular glutamine during sepsis? JPEN J Parenter Enteral Nutr 1995 Jul-Aug;19(4):279-85
12. Hammarqvist F, Wernerman J, von der Decken A, Vinnars E.
Alanyl-glutamine counteracts the depletion of free glutamine and the postoperative decline in protein synthesis in skeletal muscle. Ann Surg 1990 Nov;212(5):637-44
13. Hankard RG, Haymond MW, Darmaun D.
Effect of glutamine on leucine metabolism in humans. Am J Physiol 1996 Oct;271(4 Pt 1):E748-54
14. Hickson RC, Czerwinski SM, Wegrzyn LE.
Glutamine prevents downregulation of myosin heavy chain synthesis and muscle atrophy from glucocorticoids. Am J Physiol 1995 Apr;268(4 Pt 1):E730-4
15. Hiscock N, Pedersen BK.
Exercise-induced immunodepression- plasma glutamine is not the link. J Appl Physiol 2002 Sep;93(3):813-22
16. Humbert B, Nguyen P, Dumon H, Deschamps JY, Darmaun D.
Does enteral glutamine modulate whole-body leucine kinetics in hypercatabolic dogs in a fed state? Metabolism 2002 May;51(5):628-35
17. Jepson MM, Bates PC, Broadbent P, Pell JM, Millward DJ.
Relationship between glutamine concentration and protein synthesis in rat skeletal muscle. Am J Physiol 1988 Aug;255(2 Pt 1):E166-72
18. Lacey JM, Wilmore DW.
Is glutamine a conditionally essential amino acid? Nutr Rev 1990 Aug;48(8):297-309
19. Lobley GE, Hoskin SO, McNeil CJ.
Glutamine in animal science and production. J Nutr 2001 Sep;131(9 Suppl):2525S-31S; discussion 2532S-4S
20. Low SY, Taylor PM, Rennie MJ.
Responses of glutamine transport in cultured rat skeletal muscle to osmotically induced changes in cell volume. J Physiol 1996 May 1;492 ( Pt 3):877-85
21. MacLennan PA, Brown RA, Rennie MJ.
A positive relationship between protein synthetic rate and intracellular glutamine concentration in perfused rat skeletal muscle. FEBS Lett 1987 May 4;215(1):187-91
22. MacLennan PA, Smith K, Weryk B, Watt PW, Rennie MJ.
Inhibition of protein breakdown by glutamine in perfused rat skeletal muscle. FEBS Lett 1988 Sep 12;237(1-2):133-6
23. Olde Damink SW, de Blaauw I, Deutz NE, Soeters PB.
Effects in vivo of decreased plasma and intracellular muscle glutamine concentration on whole-body and hindquarter protein kinetics in rats. Clin Sci (Lond) 1999 Jun;96(6):639-46
24. Petersson B, von der Decken A, Vinnars E, Wernerman J.
Long-term effects of postoperative total parenteral nutrition supplemented with glycylglutamine on subjective fatigue and muscle protein synthesis. Br J Surg 1994 Oct;81(10):1520-3
25. Shabert JK, Winslow C, Lacey JM, Wilmore DW.
Glutamine-antioxidant supplementation increases body cell mass in AIDS patients with weight loss: a randomized, double-blind controlled trial. Nutrition 1999 Nov-Dec;15(11-12):860-4
26. van Hall G, Saris WH, van de Schoor PA, Wagenmakers AJ.
The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man. Int J Sports Med 2000 Jan;21(1):25-30
27. Varnier M, Leese GP, Thompson J, Rennie MJ.
Stimulatory effect of glutamine on glycogen accumulation in human skeletal muscle. Am J Physiol 1995 Aug;269(2 Pt 1):E309-15
28. Vom Dahl S, Haussinger D.
Nutritional state and the swelling-induced inhibition of proteolysis in perfused rat liver. J Nutr 1996 Feb;126(2):395-402
29. Wusteman M, Tate H, Elia M.
The use of a constant infusion of [3H]phenylalanine to measure the effects of glutamine infusions on muscle protein synthesis in rats given turpentine. Nutrition 1995 Jan-Feb;11(1):27-31
30. Zachwieja JJ, Witt TL, Yarasheski KE.
Intravenous glutamine does not stimulate mixed muscle protein synthesis in healthy young men and women. Metabolism 2000 Dec;49(12):1555-60
31. Zorzano A, Fandos C, Palacin M.
Role of plasma membrane transporters in muscle metabolism. Biochem J 2000 Aug 1;349 Pt 3:667-88
---------------------------------------------------------------------------------
Appetite For Construction
Building Results From Research
by John M. Berardi
Writer and scientist John Berardi has established quite a following here at Testosterone. He's intelligent, innovative, and talented, not to mention darn purty, if you're into that kind of thing. He also seems to know a thing or two about nutritional biochemistry and metabolism, hence this column about nutrition. If you agree that the key to success in bodybuilding is diet, then John is your "go to" guy.
Should I Spend my Hard-Earned Money on Glutamine or Hookers?
Q: In a recent T-mag article, glutamine was described as pretty much worthless if you're already taking care of protein and post-workout protein/carb/amino needs. What's your opinion? Is glutamine overrated?
A: Well, for starters, glutamine is the most abundant free amino acid…
Aww hell; I'm not going start my response off with the standard opening line that just about everyone uses to indirectly affix grandiose importance to this amino acid! Sure, it's conditionally essential (meaning that although it's not absolutely necessary in the diet, our requirements for glutamine can exceed our production of it in certain conditions).
Yes, it makes up 2/3 of the muscle's free amino acid pool (which is a pretty damn small part of the muscle's total amino acid content anyway) and sure, glutamine has been shown to have some pretty amazing benefits in wasting conditions, postoperative patients, and in TPN (total parenteral nutrition).
But as bodybuilding/fitness writers, it's about time we put aside this useless trivia and discuss the utility of glutamine supplementation for athletes, weight lifters, etc. A few years ago there were no data and therefore we could speculate all we wanted about the theoretical potential of glutamine supplementation. But nowadays, we've got the data and the data demonstrate that our theories may have been wrong.
To this end, I applaud my good friend David Barr on his excellent articles (Glutamine — Destroying the Dogma Part I and Part II) that revealed that despite all the conjecture about how glutamine supplementation may help increase muscle mass, muscle strength, and prevent overtraining, each and every research investigation examining the effects of glutamine supplementation on exercise performance, body composition, and protein degradation has shown that it offers no benefit. Because of the great job that Dave did in his literature review, I certainly don't have to provide a reference list — they're all right there at the end of his article.
To reiterate a few of the key points that Dave brought up in his article and that I brought up at the SWIS seminar:
• A high protein diet provides a big whack of glutamine as it is. In fact, if you follow standard bodybuilding protein recommendations, about 10% of your total dietary protein intake is composed of glutamine (milk proteins are composed of somewhere between 3 — 10% glutamine while meat is composed of about 15% glutamine). This means that a high protein diet (400g/day) already provides me with about 40g of glutamine.
• While the theorists still cling to the idea that since glutamine helps clinical stress, it might help with exercise stress, it‚s important to note that exercise stress has got nothin‚ on surgery, cancer, sepsis, burns, etc. For example, when compared with downhill running or weight lifting, urinary nitrogen loss is 15x (1400%) greater in minor surgery, 25x (2400%) greater in major surgery, and 33x (3200%) greater in sepsis. When it comes to the immune response, it‚s about 9x (800%) greater with surgery. When it comes to metabolic increase, it‚s 7x (600%) greater with burn injury, and when it comes to creatine kinase release; it‚s about 2x (100%) greater with surgery. As I said, exercise has got nothin‚ on real, clinical stress. It‚s like trying to compare the damage inflicted by a peashooter and that inflicted by a rocket launcher.
• The major studies examining glutamine supplementation in otherwise healthy weightlifters have shown no effect. In the study by Candow et al (2001), 0.9g of supplemental glutamine/kg/day had no impact on muscle performance, body composition, and protein degradation. Folks, that's 90g per day for some lifters.
• The majority of the studies using glutamine supplementation in endurance athletes have shown little to no measurable benefit on performance or immune function.
• And with respect to glycogen replenishment in endurance athletes, it's interesting to note that the first study that looked at glycogen resynthesis using glutamine missed a couple of things. Basically, the study showed that after a few glycogen depleting hours of cycling at a high percentage of VO2 max interspersed with very intense cycle sprints that were supramaximal, a drink containing 8g of glutamine replenished glycogen to the same extent as a drink containing 61g of carbohydrate.
The problem was that during the recovery period, a constant IV infusion of labeled glucose was given (i.e., a little bit of glucose was given to both groups by IV infusion). While this isn't too big of a deal on its own since the infusion only provided a couple of grams of glucose, the other problem is that during glycogen depleting exercise, a lot of alanine, lactate, and other gluconeogenic precursors are released from the muscle.
What this means is that there's a good amount of glucose that will be formed after such exercise, glucose that will be made in the liver from the gluconeogenic precursors and that will travel to the muscle to replenish glycogen. Therefore, without a placebo group that receives no calories, carbohydrates, or glutamine, we have no idea of knowing whether or not the placebo would have generated the same amount of glycogen replenishment as the glutamine group or the glutamine plus carbohydrate group. To say it another way, perhaps there's a normal glycogen replenishment curve that was unaffected by any of the treatments.
• And finally, with respect to the claims that glutamine might increase cell swelling/volume (something I once believed was a reality), we decided to test this theory out in our lab using multifrequency bioelectric impedance analysis as well as magnetic resonance spectroscopy. The pilot data that's kicking around has demonstrated that glutamine supplementation has no effect on total body water, intracellular fluid volumes, or extracellular fluid volumes (as measured by mBIA) and has no effect on muscle volume (as measured by nMRS).
Therefore, at the present time, I think it's safe to conclude that glutamine supplementation probably offers little to no benefit with respect to athletic performance or body composition when given to well-fed, healthy athletes. But I don't want to totally burst anyone's little glutamine bubble. After all, I'm not saying that glutamine supplementation is totally worthless. As Dave Barr pointed out in his article, there may be some circumstances in which glutamine supplementation is of benefit. Here are some of them:
• Steroid users who are improperly coming off a cycle might need some. When coming off a steroid cycle, blood Testosterone concentrations are dismally low while cortisol levels become quite elevated. If said steroid user continues training (which he/she must to try to preserve their muscle mass), the catabolic stimulation might be significant. It still doesn't approach clinical catabolism but it may just become bad enough that some extra glutamine might help. This is just a guess, however.
• When trying to get really lean, many bodybuilders restrict energy intake and increase exercise volume and might need some glutamine. This type of energy deficit may signal the body to begin using protein as an energy source, cutting into valuable muscle resources. In addition this catabolic stimulus will be compounded by the exercise stress and may lead to excess catabolism. Perhaps glutamine may help out in these scenarios. Again, a guess.
• In elite endurance athletes training intensely 2 or 3 times in a given day, I might prescribe some. Although I rarely recommend glutamine to my clients, my elite cross country skiers are encouraged to take it mostly during their trips to altitude camp and for glacier training. These athletes train 2-3 times per day for a week or two at a time while living in tents on a glacier at altitude. Add on the fact that nutrition on such excursions is bare bones, so that's some stress that glutamine might help with.
• When injured and trying to prevent wasting or facilitate wound/soft tissue injury, take some. Williams et al (2002) demonstrated that daily supplementation with 3g of HMB, 14g of glutamine, and 14g of arginine can lead to increased wound healing.
So when all is said and done, I pretty much agree with Dave's appraisal of the value of glutamine supplementation for well-fed weightlifters and bodybuilders. Considering how much protein most bodybuilders consume, additional glutamine supplementation are probably worthless. However, like any other question, there isn't a black and white answer. There do remain a few situations, as discussed above, that glutamine might be a supplement to consider. Personally, I only prescribe it to my skiers during altitude and glacier training, to steroid users coming "off," to bodybuilders during the last few weeks of competition dieting, and to people who are injured and trying hard to recover. And, of course, to those with legitimate wasting conditions. If you don't fall into any of these categories, spend your money on more groceries.
-Animated.gif)
Please Scroll Down to See Forums Below 
.jpg "Research Chemical Sciences")
.png "Research Chemical Sciences")
