L-Glutamine question... [Forum Archive]

-->

Pages: 1

L-Glutamine question...

(Click here to view the original thread with full colors/images)

Posted by: Tha Don

1)When should i take l-glutamine? (what times of day?)
2)How much should i take? and...
3)What should i take it with? (or what should i use as a transport system?)

and if theres anything else I ought to know plz say...

thanks in advance

peace

Posted by: TheRoyalOne

The jury is still out on this one.

Some say 5g/30min before a workout and then 5g after

Others suggest 5-15g/day spread out over 2-3 doses with the last dose right before bed.

Many protein drinks contain up to 3g per serving so you may already get it that way.

Posted by: plouffe

Yeah 5g before, 5g after, and 5g before sleep. That's probally what most would suggest.

Posted by: TheRoyalOne

Quote:

Originally posted by plouffe
Yeah 5g before, 5g after, and 5g before sleep. That's probally what most would suggest.

That's how I usually do it.

Posted by: Tha Don

Quote:

Originally posted by plouffe
Yeah 5g before, 5g after, and 5g before sleep. That's probally what most would suggest.

sounds good

so 5g in my pre workout shake (whey and oatmeal)?

5g in my post workout shake (whey iso, maltodextrin, creatine)

and 5g with my bedtime meal? or after it?

at bedtime should i just have it with water? juice? or a whey shake or what?

what is the optimal transport/delivery for glutamine?

peace

Posted by: TheRoyalOne

Quote:

Originally posted by young d
.....

what is the optimal transport/delivery for glutamine?

peace

Never thought about that one. I just use water (come to think of it, I don't drink anything else....most of the time

)

Posted by: Twin Peak

1) Never.
2) None.
3) Irrelevant.

Posted by: atherjen

Quote:

Originally posted by Twin Peak
1) Never.
2) None.
3) Irrelevant.

explanation?

Posted by: prolangtum

Quote:

Originally posted by Twin Peak
1) Never.
2) None.
3) Irrelevant.

Si Senor Steve

Posted by: Prince

Quote:

Originally posted by atherjen
explanation?

don't get him started.

I take Glutamine just like a take a Multi-Vitamin, B-Vitamins, Extra C, and every other pill I pop twice per day.

I do not expect to see any immediate effects from it, but I do believe it is worth taking.

Posted by: pood

from reading the forums and different websites

i've narrowed it down to this

glutamine before workout
creatine afterwards

off days

creatine morning, glutamine at night

Posted by: atherjen

Quote:

Originally posted by Prince
don't get him started.

I take Glutamine just like a take a Multi-Vitamin, B-Vitamins, Extra C, and every other pill I pop twice per day.

I do not expect to see any immediate effects from it, but I do believe it is worth taking.

ohh yess Im well aware that MANY people are against supplementing with it now these days. Nevertheless I continue to take it no matter what others have to say,... but I do enjoy hearing the sides!

Posted by: Twin Peak

Jen, there are several long threads here, discussing the merits (or lack thereof). There are several more threads on Avant, making the same arguments, and a few others, and offering numerous studies establishing the lack of efficacy of glutamine for increasing, or preserving, LBM.

Posted by: atherjen

Quote:

Originally posted by Twin Peak
Jen, there are several long threads here, discussing the merits (or lack thereof). There are several more threads on Avant, making the same arguments, and a few others, and offering numerous studies establishing the lack of efficacy of glutamine for increasing, or preserving, LBM.

in that case I have some searching and reading to do.

Posted by: Twin Peak

Yep.

Posted by: DrChiro

Glutamine is the most abundant amino in muscle...it also can be used as a fuel source for the muscle.

It is depleted significantly during training and can lead to muscle breakdown (catabolism) if not replenished.

Whey protein is notoriously low in glutamine (unless it is added back in or combined with casiene or soy) so if whey is your main source of protein, glutamine is a good addition.

when taking individual aminos, like at night, they are best taken on an empty stomach. To get the GH releasing effect you must not have any sugar either.

I usually take 5g before bed with water on an empty stomach.
I take 5g before am cardio on empty stomach
And my shake has added glutamine so i take that afer i workout.

hope this helps!

Posted by: tk...

Quote:

Originally posted by DrChiro
when taking individual aminos, like at night, they are best taken on an empty stomach. To get the GH releasing effect you must not have any sugar either.

u beat me to it. Just a little add on , when taken without sugar at night, it have been proven that l-glutamine increases GH levels by 15%.

Posted by: Testosterone

It works best for me when I take POST WORKOUT 10 grams in my Whey Protein Shake and another 10 grams before retiring to bed.
It mainly decreases muscle soreness IMO.

Posted by: Dale Mabry

There is lack of compelling clinical evidence supporting the use of glutamine for anything other than helping out the immune system in times of stress, generally in immuno-suppressed people. People generally point to it's abundance in skeletal muscle as proof that supplementing with it will help improve LBM. This thinking is flawed considering that muscle is mostly comprised of water and drinking gallons upon gallons of it will not cause your muscles to grow.

Posted by: Twin Peak

Quote:

Originally posted by Dale Mabry
There is lack of compelling clinical evidence supporting the use of glutamine for anything other than helping out the immune system in times of stress, generally in immuno-suppressed people. People generally point to it's abundance in skeletal muscle as proof that supplementing with it will help improve LBM. This thinking is flawed considering that muscle is mostly comprised of water and drinking gallons upon gallons of it will not cause your muscles to grow.

Sanity.

Posted by: Dale Mabry

The way I look at it, if it gives you peace of mind, go ahead and buy it, it is pretty cheap. IMO, you are better off buying EFAs or creatine with the money, but that's just me. BTW, I used to take this stuff 10g upon awakening and 10g pre workout years ago, but once I searched Pubmed and Medline for evidence to support it's use, I dropped it.

Posted by: gopro

I will not argue on the merits of glutamine. Suffice to say that I use it...a whole lot...everyday. Currently I am taking 5 g in between every meal of the day!

Posted by: Twin Peak

Ronnie Coleman takes it 5 times a day too, so it must be worthwhile.

Posted by: Dale Mabry

I didn't know Ronnie was on it, I am getting some!

Posted by: Testosterone

NOT JUST RONNIE OR JAY....EVERY PRO USES IT IMO....(SINCE EVERY PRO TRAINS HIMSELF (POUNDS HIMSELF) INTO SUBMISSION. THAT'S SOME SERIOUS STRESS.

Posted by: Prince

Quote:

Originally posted by gopro
I will not argue on the merits of glutamine. Suffice to say that I use it...a whole lot...everyday. Currently I am taking 5 g in between every meal of the day!

I take three 5 gram servings per day with my protein shakes, morning, post work-out and before bed, and I will continue to do so.

Posted by: gr81

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.

I could go on and on about the uselessness of glutamine but we have been there and done that. It is a waste of money in most situations IMO and there are studies to back that up.

Posted by: Prince

GLUTAMINE - A Supplement Waiting for Science to Catch Up?

Every month we look at a new supplement, and up until now it’s always been on a topic that I have researched in the past and had a real personal interest in. Although I have used glutamine in the past, like many of you I just accepted that there was a host of literature that proved its credentials for use in sports nutrition.

For me its use has been in the area of immune system functioning and optimising my post exercise recovery. The conclusions based on the current peer reviewed data may surprise you, as the window for the potential application of this amino acid to significantly aid muscle growth and recuperation are shorter than you may realise!

Here is a supplement that’s been hitting the headlines for at least a decade, offering a host of physiological advantages including increased cell volume, improved protein balance, immune function, pH regulation, and acting as an excitatory neurotransmitter that can aid mental function. Well let’s take a look at the evidence guys and see “what’s the TRUTH”.

There is no doubt that the physiological importance of the amino acid L-glutamine for promoting and maintaining cell function is accepted across the scientific community. It is now well known that a large number of tissues and cells in the body utilize glutamine at high rates, and that glutamine utilization is essential for their function. Because of the vast quantity of literature on glutamine in this issue of Ironmagazine the focus of the review must be selective, with the most influential topics reflecting you guys the readers of Ironmagazine. I believe these areas to be protein synthesis, cell swelling, and immune function (can’t train if you are ill right!).

Glutamine Origin & Function

The immediate product of glutamine metabolism in most cells is glutamate, (see fig.1) which is produced by the action of glutaminase. Glutamine is the most abundant extra-cellular amino acid and its breakdown product glutamate is the most abundant in the intra-cellular environment [1]. Glutamine is utilized by many tissues including, kidneys, gut, and some cells of the immune system. To maintain these extreme demands glutamine must be synthesised by several organs, including skeletal muscle, kidneys, liver, lungs, and heart. The most important site of glutamine metabolism is skeletal muscle. In skeletal muscle glutamine can be synthesised by a variety of biochemical reactions including protein degradation or from the combination of 2-oxoglutarate and branched chain amino acids (leucine, isolucine, valine); it can just as well be taken from the plasma in its whole form or via the deamination of proteins [2].

Don’t stress it: Immune function

It is now widely accepted that glutamine is utilized at high rates by isolated cells of the immune system such as lymphocytes, macrophages and neutraphils [3,4]. These cells can be placed under considerable pressure during situations resulting in elevated stress with the consequence being immune-suppression. Exercise is one form of physiological stress that could lead to immune system suppression, but is there a link between glutamine stores and its optimum functioning?

The effect of acute exercise on plasma glutamine concentration appears to be dependent to a large extent to both the intensity and duration of the exercise bout. After prolonged (2>hrs duration) exhaustitive exercise there is generally a small but significant decrease in circulating plasma glutamine concentrations [5,6,7]. Evidence suggests that the suppression of glutamine may remain for up to 4 hours upon the cessation of exercise [8]. Although in some situations this has been shown to be the case in many others it has not. Following ultra-triathlon, plasma glutamine was shown not to change [9], single bouts of high intensity exercise have been shown to both increase and shown no change [10,11]. So why all the confusion between studies? In essence this reflects the fact that measurements are mainly based on plasma analysis rather than assessment of changes within the intracellular environment i.e. “muscle glutamine stores”. In situations where muscle glutamine has been measured, a decrease is seen in many of the above exercise situations. What is still not well understood is why plasma glutamine levels can decrease while muscle glutamine is being released into the plasma (this maybe due to uptake of glutamine by the kidneys to maintain pH). The latest data suggests that in people with a long history of exercising and atypical over-trainers there is a change in the transport system leading to a decrease in the rate of glutamine release from skeletal muscle.

The chronicity of the physiological stress seems to be directly related to the severity of the immune suppression we can experience. This has been shown to be never truer than in clinical environment, and the severe trauma of sepsis and burns [12]. The largest decline reported in plasma glutamine is in severe burns victims where plasma concentration can fall massively from 490 - 200mM [11]. We know of many studies that have shown a direct relationship between glutamine loss and this form of excessive trauma and the need for supplemental glutamine. However to place this in context acute exercise only leads an average decline of only 100mM; much less of a fall and a decline that can be quickly replenished in a health subject. As we already know glutamine feeds a variety immune functioning cells, its is therefore important to understand if the exercise related decrease in plasma glutamine can have an immuno- suppressive effect, and if supplementation could ameliorate these negative consequences.

Lymphocyte Activated Killer cell activity (LAK) an immune cell type that destroy invading organisms, have been shown to be directly linked to glutamine concentrations. Juretic et al [13] discovered that depression of glutamine concentrations negatively affected the LAK activity. In an applied situation measurements of declining serum glutamine taken following a triathlon resulted in a parallel decline in LAK [14]. Many other immune responses have been proposed to be effected including cytokines and macrophages, however although there is a selection of literature linking glutamine with the immune system it is still unknown weather there is a causal relationship between decreased glutamine stores and immuno-suppression or vice versa. One possible way to elucidate this is through monitoring the effects of L-glutamine supplementation of which we will examine later (If you cannot wait skip forward a few paragraphs).

Cell Swelling: Turning up the Anabolic signal

Cellular swelling is often a symptom of a change in the osmotic gradient within the cell. What this means is that if you increase the concentration of a compound outside of the cell membrane above that found inside of the cell, there will be a movement of this compound until extracellular and intracellular contents are equal [15]. The movement of these compounds / solutes result in the uptake of water as they are transported inside the cell and hence a transient expansion of cellular volume (See figure.2).

Recent evidence suggests that the state of cellular hydration (cell volume) is an import factor in the control of many important cellular functions. These include modulation of hormones, oxidative stress, and gene expression to name but a few. Several compounds have been shown to have a significant effect on cellular volume. The effect these amino acids have on glycogen synthesis and inhibition of proteolysis can be mimicked by bringing about similar changes in cell volume [16,17,18]. This indicates that many of the effects these amino acids exert can be accounted primarily due to their cell volumizing properties.

Cell swelling also inhibits protein breakdown but conversely cell shrinkage stimulates breakdown [19]. Glutamine has been shown to be a potent player for enhancing cellular swelling [20] (see figure.3). The mechanisms proposed for improved protein turnover as mediated via glutamine induced cell swelling are two-fold. Firstly it may influence the function of cyclic AMP, a chemical messenger associated with many cellular functions including the inhibition of protein synthesis as such, cell swelling may prevent or enhance protein synthesis. Secondly it may have a direct effect on cellular stability [21] however I doubt this hypothesis as recent studies have shown glutamine to have little effect on myofibrillar damage over the short term [22], longer term studies are still needed. Other factors such as nitrogen balance will be affected through glutamine supplementation and this in its own right will have a significant impact on protein synthetic rates.

The influence of L-Glutamine supplementation

Immune Function

Several research studies have investigated the suggestion that exogenous provision of glutamine supplementation may be beneficial by preventing the impairment of immune function following endurance exercise. Castell [23] was one of if not the primary study demonstrating the influence of glutamine supplementation following exercise. A 5g dose was given immediately post race and 2hrs proceeding the event. Plasma glutamine was still depressed by 20% in both groups although based on questionnaires 80% of athletes reported no incidence of infection up to 7 days post event, were only 48% of the placebo group remained free of infection. However in a follow up study no significant difference in plasma glutamine was demonstrated between swimmers who did or did not develop upper respiratory tract infection (URTI) following and increase in the intensity of their training schedule [5].

It has been hypothesised that the dose of glutamine was not enough to ameliorate the decline in plasma glutamine concentrations, so a new dose protocol was needed. A dose routine using 100mg/kg BW was used 30min pre, immediately post, and 30mins post exercise [24]. The exercise consisted cycling for 60,45, and 30 mins with 2 hr recovery periods. The glutamine supplemented group maintained plasma concentrations above pre supplement levels, whilst the placebo group decrease by about 20% (as in the previous study above). Although the supplemented group maintained plasma glutamine concentration no differences were shown between the groups lymphocytes, leucocytes, or LAK activities, which are all known indicators of immune system function. This data demonstrates that although plasma glutamine concentrations were attenuated the influence of supplementation did not diminish post exercise immuno-suppresion characterised by decreased lymphocyte concentration and LAK activity.

There are two other major factors I would like to draw you attention two as regards the hypothesis of L-glutamine supplementation and immuno-suppression. Firstly it has been shown that in-vitro when we decrease the glutamine availability to lymphocytes to the lowest possible levels measured post exercise (300mM) their function was just as efficient as at concentrations similar to that demonstrated at rest (600mM). Secondly data from researchers at the Copenhagen Muscle Research Centre (CMRC) have shown that following an acute bout of cycling plasma glutamine levels decrease as expected, however the concentration in many of the immune cells was maintained and possibly increased. Therefore using the current dosing regimes, oral glutamine ingestion does not positively influence immune functioning in exercising populations.

Cell Swelling & protein sparing

To date there is very little direct data on L-glutamine feeding and protein rates in humans, what you will see quoted is a myriad of papers on malnutrition, AIDS, and people with gastrointestinal disorders. These hardly represent the exercising population and I won’t insult your intelligence by quoting what they have found. I could only really find one real study that has looked at the implication of glutamine supplementation and exercise performance for the resistance trained athlete. Antonio et al [25] investigated the possibility of high dose glutamine supplementation on weightlifting performance (one hour after ingestion) as defined by 2 sets of leg press (200% Bwt) and 2 sets of bench press (100% Bwt). No significant differences were found in the average number of reps performed between all groups. There is no reason why glutamine use would affect this form of performance, other than the far-reaching possibility of controlling/enhancing intracellular pH (ye glutamine may do this also). In this regard there are much more efficient extracellular and intracellular buffers. L-glutamine may also affect proteolysis by inhibiting the catabolic effects of cortisol. Whilst in clinical situations this may have a significant place in the total impact of a sound nutritional program in the experienced athlete I am not as convinced. Many studies have shown cortisol control has no direct impact on exercise performance [26] and possibly zero impact even if we could depress our cortisol levels, as experienced lifters produce less cortisol then their associated sedentary counterparts [27] buts that’s another story…

Glutamine a household name…but where do we go from here?

So what can we take away form the current research on glutamine that may help us improve performance, recovery, and the associated benefits of muscle growth and fat loss? Well there is no doubt that under very stressful conditions the bodies needs for glutamine can outstrip the capacity for production, leading to decreased intramuscular glutamine contents. In disease states associated with excessive muscle catabolism (AIDS for example); glutamine supplementation may maintain a positive nitrogen balance and sustain bodyweight. However the oral infusion of glutamine in healthy subjects has been shown to have no effect on retaining nitrogen balance [28]. Although this data seems to paint to a pretty bleak picture of glutamine, the truth is that much of the research has shown poor physiological benefits for generally athletic population because of a series of factors:

No methodical approach to dosing to find an optimal level to bring about favourable effects.

Many of the studies are short duration and a possible accumulative benefit of glutamine over time is unknown.

The influence of high-dose glutamine ingestion on trained subjects and cellular swelling are still awaiting investigation.

Studies still need to be performed on those athletes that are overtrained and are consistently effected by repeat viral infection. Can glutamine aid in the recovery of repeat infection and cumulative immuno-suppression?

5. Finally the most important factor is that many of the studies on glutamine are significantly influenced by the nutritional state of the study participants. An example of this is the anti-proteolytic effects exerted through the supplementation of glycine. In the fed state its anti-proteolytic effects is only about one third of that found after 24hrs of starvation.

My recommendations would to be make sure you take in at least 5g of glutamine each day as an assurance policy in conjunction with you usual nutritional regime. To try to have a real impact on recovery and maintaining intracellular glutamine stores the relatively high dose of 100mg/kg (equivalent to 7-10g a day) taken pre, post and 30mins will guarantee this result, although at a financial cost. So in essence science has a ways to go to prove the efficacy of glutamine as a vital sports supplement, but evidence is on the way especially in the field of antioxidant capacities and free radical mediated muscle damage prevention [29]. Until the next series of well-designed studies are released I am sure many companies will still promote this important amino acid as one of the best ergogenics out there, but now you know the facts how you use them regarding your core supplement choice is up to you!

--------------------------------------------------------------------------------

REFERENCES

1.P.Newsholme et al, “Glutamine and glutamate as vital metabolites,” Braz J Med Biol Res, 36 (2003): 153 -163
2.M.Stumvoll et al, “Role of glutamine in human carbohydrate metabolism in kidney and other tissues,” Kid Int. 5 (1999): 778 - 779
3.M.Elia et al, “ Amino acid metabolism in muscle and in the whole body of man before and after ingestion of a single mixed meal,” Am J Clin Nutr. 49 (1989): 1203 - 1210
4.S.Yoshida et al, “Effects of total parental nutrition, systemic sepsis, and glutamine on gut mucosa in rats,” Am J Physiol. 163 (1992): E368 – E373
5.L.M.Castell et al, “Some aspects of the acute phase response after a marathon race, and the effects of glutamine supplementation,” Eur J Appl Physiol. 73 (1997): 47 - 53
6.J.Decombaz et al, “Biomechanical changes in a 100km run: free amino acids, urea and creatinine,” Eur J Appl Physiol. 73 (1979): 61 - 72
7.M.Parry-Billings et al, “Plasma amino acid concentration in the over-training syndrome: Possible effects on the immune system,” Med Sci Sports Ex. 24 (1992): 1353 - 1358
8.N.His***** et al, “Exercise-induced immuno-depression – plasma glutamine not the link,” J Appl Physiol. 93 (2002): 813 - 822
9.M.Lehman et al, “Serum amino acid concentration in nine athletes before and after the 1993 Colmar ultra-triathlon,” Int J Sports Med. 16 (1995): 155 - 159
10.D.Keast et al, “Depression of plasma glutamine concentration after exercise stress and its possible influence on the immune system. Med J Aust. 162 (1995): 15 - 18
11.M.Parry-Billings et al, “Does glutamine contribute to majour burns?,” Lancet. 336 (1990): 523 -525
12.R.J.Smith, “Glutamine metabolism and its physiological importance,” JPEN.(1990):14
13.A.Juretic et al, “Glutamine requirements in the generation of the lymphokine – activated killer cells,” Clin Nutr. 13 (1994): 42 - 49
14.T.Rohde et al, “The immune system and serum glutamine during triathlon,” Eur J Appl Physiol. 74 (1996): 428 – 434
15.D.Haussinger, “The role of cellular hydration in the regulation of cell function,” J Biochem. 313 (1996): 697 - 710
16.C.Hallbrucker, “Control of hepatic proteolysis by amino acids. The role of cell volume,” Eur J Biochem. 197, 3 (1991): 717 - 724
17.A.Baquet, “Swelling of rat hepatocytes stimulates glycogen synthesis,” J Biol Chem. 15, 265 (1990): 955-959
18.D.Haussinger et al, “Involvement of microtubles in the swelling-induced stimulation of transcellular taurocholate transport in perfused rat liver,” J Biochem. 15,291 (1993): 355 - 360
19.A.J. Meijer, “Cell swelling and the sensitivity of autophagic proteolysis to inhibition by amino acids in isolated rat hepatocytes,” Eur J Biochem. 215,2 (1993): 449 - 454
20.J.Kruppa, “Differential kinetics of changes in the state of phosphorylation of ribosomal protein S6 and in the rate of protein synthesis in MPC 11 cells during tonicity shifts,”EMBO. 3,1 (1984): 95 - 100
21.D.Haussinger et al, “Effect of hepatocyte swelling on microtubule stability and tubulin mRNA levels,” Biochem Cell Biol. 72, 1-2 (1994): 12 -19
22. glutamine myocellular stability ref….
23.L.M.Castell et al, “Does glutamine have a role in reducing infections in athletes?,” Eur J Appl Physiol. 73 (1996): 488 - 490
24.T.Rhode et al, “Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Ex. 30 (1997): 856 - 862
25.J.Antonio et al, “ The effects of high-dose glutamine ingestion on weightlifting performance,” J Strength Cond Res. 16,1 (2002): 157 -160
26.P.Del Corral et al, “Metabolic effects of low cortisol during exercise in humans,” J Appl Physiol. 84,3 (1998): 939 - 947
27.J.L.McMillan et al, “20-hour physiological responses to a single weight-training session,” J Strength Con Res. 7,1 (1993): 9-21
28.T.R.Zeigler et al, “Safety and metabolic effects of L-Glutamine administration in humans. JPEN. 14,4 (1990): 137S -146S
29.U.B.Flaring et al, “Glutamine attenuates post-traumatic glutathione depletion in human skeletal muscle.Clin Sci. 104,3 (2003): 275 - 282

Posted by: gr81

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 dbmuscle@hotmail.com.

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

Posted by: gopro

Quote:

Originally posted by gopro
I will not argue on the merits of glutamine. Suffice to say that I use it...a whole lot...everyday. Currently I am taking 5 g in between every meal of the day!

I repeat...

Posted by: prolangtum

Ill stick to what has worked for me for $30 (about the cost of economical good quality glutamine). Ill just buy some nice top sirloin. Glutamine does not go good with salad.

Posted by: Dale Mabry

I am making no directed comment at either article, but if you are going to take the trouble of writing a well-referenced article, why would you not proofread it for spelling and grammatical errors?

Posted by: gopro

Quote:

Originally posted by prolangtum
Ill stick to what has worked for me for $30 (about the cost of economical good quality glutamine). Ill just buy some nice top sirloin. Glutamine does not go good with salad.

Well, I hit the glutamine about an hour before the sirloin and salad! Damn pro, you made me hungry!

(Click here to view the original thread with full colors/images)

Content Relevant URLs by vBSEO 3.1.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38