Glutamine is Worthless

redspy

Effect of glutamine supplementation combined with resistance training in young adults.

Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T.

College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.

The purpose of this study was to assess the effect of oral glutamine supplementation combined with resistance training in young adults. A group of 31 subjects, aged 18-24 years, were randomly allocated to groups (double blind) to receive either glutamine (0.9 g x kg lean tissue mass(-1) x day(-1); n = 17) or a placebo (0.9 g maltodextrin x kg lean tissue mass(-1) x day(-1); n = 14 during 6 weeks of total body resistance training. Exercises were performed for four to five sets of 6-12 repetitions at intensities ranging from 60% to 90% 1 repetition maximum (1 RM). Before and after training, measurements were taken of 1 RM squat and bench press strength, peak knee extension torque (using an isokinetic dynamometer), lean tissue mass (dual energy X-ray absorptiometry) and muscle protein degradation (urinary 3-methylhistidine by high performance liquid chromatography). Repeated measures ANOVA showed that strength, torque, lean tissue mass and 3-methylhistidine increased with training (P < 0.05), with no significant difference between groups. Both groups increased their 1 RM squat by approximately 30% and 1 RM bench press by approximately 14%. The glutamine group showed increases of 6% for knee extension torque, 2% for lean tissue mass and 41% for urinary levels of 3-methylhistidine. The placebo group increased knee extension torque by 5%, lean tissue mass by 1.7% and 3-methylhistidine by 56%. We conclude that glutamine supplementation during resistance training has no significant effect on muscle performance, body composition or muscle protein degradation in young healthy adults.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 11822473 [PubMed - indexed for MEDLINE]

redspy

Should I Spend my Hard-Earned Money on Glutamine or Hookers?

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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, its 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, its about 9x (800%) greater with surgery. When it comes to metabolic increase, its 7x (600%) greater with burn injury, and when it comes to creatine kinase release; its about 2x (100%) greater with surgery. As I said, exercise has got nothin on real, clinical stress. Its 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.

http://www.johnberardi.com/articles/..._nov082002.htm

redspy

J Strength Cond Res 2002 Feb;16(1):157-60
The effects of high-dose glutamine ingestion on weightlifting performance

Antonio J, Sanders MS, Kalman D, Woodgate D, Street C.

Sports Science Laboratory, University of Delaware, Newark, Delaware 19716, USA.

The purpose of this study was to determine if high-dose glutamine ingestion affected weightlifting performance. In a double-blind, placebo-controlled, crossover study, 6 resistance-trained men (mean +/- SE: age, 21.5 +/- 0.3 years; weight, 76.5 +/- 2.8 kg(-1)) performed weightlifting exercises after the ingestion of glutamine or glycine (0.3 g x kg(-1)) mixed with calorie-free fruit juice or placebo (calorie-free fruit juice only). Each subject underwent each of the 3 treatments in a randomized order. One hour after ingestion, subjects performed 4 total sets of exercise to momentary muscular failure (2 sets of leg presses at 200% of body weight, 2 sets of bench presses at 100% of body weight). There were no differences in the average number of maximal repetitions performed in the leg press or bench press exercises among the 3 groups. These data indicate that the short-term ingestion of glutamine does not enhance weightlifting performance in resistance-trained men.

redspy

Int J Sports Med 2000 Jan;21(1):25-30 Related Articles, Links


The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man.

van Hall G, Saris WH, van de Schoor PA, Wagenmakers AJ.

Department of Human Biology, Maastricht University, The Netherlands. RH01769@RH.DK

The present study investigated previous claims that ingestion of glutamine and of protein-carbohydrate mixtures may increase the rate of glycogen resynthesis following intense exercise. Eight trained subjects were studied during 3 h of recovery while consuming one of four drinks in random order. Drinks were ingested in three 500 ml boluses, immediately after exercise and then after 1 and 2 h of recovery. Each bolus of the control drink contained 0.8 g x kg(-1) body weight of glucose. The other drinks contained the same amount of glucose and 0.3 g x kg(-1) body weight of 1) glutamine, 2) a wheat hydrolysate (26% glutamine) and 3) a whey hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20% during recovery with ingestion of the control drink, no changes with ingestion of the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free glutamine drinks. The rate of glycogen resynthesis was not significantly different in the four tests: 28 +/- 5, 26 +/- 6, 33 +/- 4, and 34 +/- 3 mmol glucosyl units x kg(-1) dry weight muscle x h(-1) for the control, glutamine, wheat- and whey hydrolysate ingestion, respectively. It is concluded that ingestion of a glutamine/carbohydrate mixture does not increase the rate of glycogen resynthesis in muscle. Glycogen resynthesis rates were higher, although not statistically significant, after ingestion of the drink containing the wheat (21 +/- 8%) and whey protein hydrolysate (20 +/- 6%) compared to ingestion of the control and free glutamine drinks, implying that further research is needed on the potential protein effect.

redspy

Metabolism 2000 Dec;49(12):1555-60 Related Articles, Links


Intravenous glutamine does not stimulate mixed muscle protein synthesis in healthy young men and women.

Zachwieja JJ, Witt TL, Yarasheski KE.

Exercise and Nutrition Program, Pennington Biomedical Research Center, Baton Rouge, LA, USA.

We investigated the effects of a glutamine-supplemented amino acid mixture on vastus lateralis muscle protein synthesis rate in healthy young men and women. Three men and 3 women (27.8 +/- 2.0 yr, 22.2 +/- 1.0 body mass index [BMI], 56.1 +/- 4.5 kg lean body mass [LBM]) received a 14-hour primed, constant intravenous infusion of L[1-13C]leucine to evaluate the fractional rate of mixed muscle protein synthesis. In addition to tracer administration, a clinically relevant amino acid mixture supplemented with either glutamine or glycine in amounts isonitrogenous to glutamine, was infused. Amino acid mixtures were infused on separate occasions in random order at a rate of 0.04 g/kg/h (glutamine at approximately 0.01 g/kg/h) with at least 2 weeks between treatment. For 2 days before and on the day of an infusion, dietary intake was controlled so that each subject received 1.5 g protein/kg/d. Compared with our previous report in the postabsorptive state, amino acid infusion increased the fractional rate of mixed muscle protein synthesis by 48% (P < .05); however, the addition of glutamine to the amino acid mixture did not further elevate muscle protein synthesis rate (ie, 0.071% +/- 0.008%/h for amino acids + glutamine v 0.060% +/- 0.008%/h for amino acids + glycine; P = .316). Plasma glutamine concentrations were higher (P < .05) during the glutamine-supplemented infusion, but free intramuscular glutamine levels were not increased (P = .363). Both plasma and free intramuscular glycine levels were increased when extra glycine was included in the infused amino acid mixture (both P < .0001). We conclude that intravenous infusion of amino acids increases the fractional rate of mixed muscle protein synthesis, but addition of glutamine to the amino acid mixture does not further stimulate muscle protein synthesis rate in healthy young men and women.

redspy

J Appl Physiol 2002 Sep;93(3):813-22 Related Articles, Links


Exercise-induced immunodepression- plasma glutamine is not the link.

His**** N, Pedersen BK.

Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark.

The amino acid glutamine is known to be important for the function of some immune cells in vitro. It has been proposed that the decrease in plasma glutamine concentration in relation to catabolic conditions, including prolonged, exhaustive exercise, results in a lack of glutamine for these cells and may be responsible for the transient immunodepression commonly observed after acute, exhaustive exercise. It has been unclear, however, whether the magnitude of the observed decrease in plasma glutamine concentration would be great enough to compromise the function of immune cells. In fact, intracellular glutamine concentration may not be compromised when plasma levels are decreased postexercise. In addition, a number of recent intervention studies with glutamine feeding demonstrate that, although the plasma concentration of glutamine is kept constant during and after acute, strenuous exercise, glutamine supplementation does not abolish the postexercise decrease in in vitro cellular immunity, including low lymphocyte number, impaired lymphocyte proliferation, impaired natural killer and lymphokine-activated killer cell activity, as well as low production rate and concentration of salivary IgA. It is concluded that, although the glutamine hypothesis may explain immunodepression related to other stressful conditions such as trauma and burn, plasma glutamine concentration is not likely to play a mechanistic role in exercise-induced immunodepression.

redspy

Effect of glutamine and protein supplementation on exercise-induced decreases in salivary IgA.

Krzywkowski K, Petersen EW, Ostrowski K, Link-Amster H, Boza J, Halkjaer-Kristensen J, Pedersen BK.

The Copenhagen Muscle Research Centre, Rigshospitalet, 2200 Copenhagen, Denmark.

Postexercise immune impairment has been linked to exercise-induced decrease in plasma glutamine concentration. This study examined the possibility of abolishing the exercise-induced decrease in salivary IgA through glutamine supplementation during and after intense exercise. Eleven athletes performed cycle ergometer exercise for 2 h at 75% of maximal oxygen uptake on 3 separate days. Glutamine (a total of 17.5 g), protein (a total of 68.5 g/6.2 g protein-bound glutamine), and placebo supplements were given during and up to 2 h after exercise. Unstimulated, timed saliva samples were obtained before exercise and 20 min, 140 min, 4 h, and 22 h postexercise. The exercise protocol induced a decrease in salivary IgA (IgA concentration, IgA output, and IgA relative to total protein). The plasma concentration of glutamine was decreased by 15% 2 h postexercise in the placebo group, whereas this decline was abolished by both glutamine and protein supplements.None of the supplements, however, was able to abolish the decline in salivary IgA. This study does not support that postexercise decrease in salivary IgA is related to plasma glutamine concentrations.

redspy

Effect of carb intake on plasma glutamine

Int J Sport Nutr 1998 Mar;8(1):49-59 Related Articles, Links


Effect of low- and high-carbohydrate diets on the plasma glutamine and circulating leukocyte responses to exercise.

Gleeson M, Blannin AK, Walsh NP, Bishop NC, Clark AM.

School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, England.

We examined the effects of a low-carbohydrate (CHO) diet on the plasma glutamine and circulating leukocyte responses to prolonged strenuous exercise. Twelve untrained male subjects cycled for 60 min at 70% of maximal oxygen uptake on two separate occasions, 3 days apart. All subjects performed the first exercise task after a normal diet; they completed the second exercise task after 3 days on either a high-CHO diet (75 +/- 8% CHO, n = 6) or a low-CHO diet (7 +/- 4% CHO, n = 6). The low-CHO diet was associated with a larger rise in plasma cortisol during exercise, a greater fall in the plasma glutamine concentration during recovery, and a larger neutrophilia during the postexercise period. Exercise on the high-CHO diet did not affect levels of plasma glutamine and circulating leukocytes. We conclude that CHO availability can influence the plasma glutamine and circulating leukocyte responses during recovery from intense prolonged exercise.

redspy

http://www.hypertrophy-specific.com...ct=ST;f=13;t=25

Here are the reasons to take glutamine.

1) Immune support. Supplemental use of glutamine, either in oral, enteral, or parenteral form, increases intestinal villous height, stimulates gut mucosal cellular proliferation, and maintains mucosal integrity. It also prevents intestinal hyperpermeability and bacterial translocation, which may be involved in sepsis and the development of multiple organ failure. One study reported that athletes reported fewer incedences of upper respiratory tract infections while supplementing with glutamine (2 grams) after they ran.

2) Gastrointestinal support. 70-80% of orally administered glutamine is absorbed into the cells of your GI tract. It remains there and is metabolised by those cells without ever reaching the blood stream (image). In sicknesses such as sepsis it has been shown to help improve survival because of improved GI tract function.

Thats pretty much it.

There is no real benefit for someone looking to build bigger muscles. That 10% of dietary glutamine that gets past the GI tract is taken up by the liver where it is converted into sugar (gluconeogenesis) and stored as glycogen in the liver.

Don't let in-vitro research fool you into thinking oral glutamine will have an effect on a healthy individuals muscle mass. Yes, glutamine does regulate protein synthesis to a certain extent under some situations. However, you can't make it happen by taking it orally. Don't let ads with some pro-bodybuilder holding a bottle of glutamine fool you. Even if that pro-bodybuilder is taking it...it isn't doing anything for him either.

Here are a couple good "in-vivo" research studies to start with:

1. 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.

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.

Keep in mind that if you are eating protein powders, especially any thing with whey in it, you are getting plenty of glutamine. The question of glutamines worth in the newsletter centered on its effect on building mass and/or strength, not anything to do with the gastrointestinal track.

In short, only 47-50% of orally administered glutamine can be expected to make it past the liver and other organs, into the blood stream. And only about 10% can be expected to reach extracellular spaces.[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. Journal of Applied Physiology. 1999 Jun;86(6):1770-7] Now, this is the main argument against glutamine. 90% of the glutamine you take orally never even makes it to your muscles. This isn't to say it is wasted. Your GI tract loves glutamine from reasons explained earlier. If you are having intestinal problems nothing is better. If you are trying to increase protein synthesis by loading glutamine, it isn't going to work

redspy

Any questions? :twisted: