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GLUTAMINE: Or should we call it GlutaGreat?

Have you ever had the experience of taking a dietary supplement, taking it consistently, making gains in the gym and not being able to connect the dots? I mean, you're training hard, your eating clean ninety-percent of the time, your using perhaps one new supplement and your strength and muscle fullness are remaining more than ever before. Can it be this mysterious white powder that you are taking a few times per day, especially on the hard training days, that is making the difference between the old you and new you? The amino acid that may just be your ergogenic king is known as glutamine. Glutamine is the most abundant amino acid circulating in your blood and hanging out in your muscles. There must be a reason why we have so much of this one (of 20) amino acids. Let's examine why this amino acid is special.

It should not be confused with Michael or Bruce Buffer
Do you watch any of the big prize fights or even the UFC? If so, you know that the Buffer brothers have the introduction aspects of all major fighting events locked up. In other words, they are the buffer between the fighters, promoters, announcers and us fans. Well, glutamine is a buffer, a big buffer in fact. When you exercise, given that the exercise is at some intensity that requires a prolonged effort (shopping with your girlfriend may be an effort and be as tiring as running a marathon, but it is not exercise), the body responds by generating ammonium ions. These ions accumulate in the muscle and eventually signal the muscle that it cannot peak perform anymore and that it is getting tired. If you buffer that ion accumulating reaction to stressful exercise, then the person exercising can train harder and longer, thus reaping the added benefit of continual stress. As a side benefit, there is some data that indicates that when lactate and hydrogen ion concentrations rise, so does the process of inhibiting muscular activity. Research does demonstrate that if you can buffer the metabolic acidosis that occurs with intensive resistance training (weight lifting), then performance output can be improved. Can anyone think of any sports where this would be a benefit beyond that of just weight lifting?

Early research in athletes has found that as little as two grams of glutamine increased the plasma bicarbonate concentrations -- meaning that yes, it acts as a buffer in a similar way that using regular bicarbonate does. When examining raw numbers, actual data from a weight training performance study, glutamine appeared to have a performance saving benefit. Let me explain, this study had college-aged males perform specific weight training exercises to failure two times for two major body parts after a thorough warm-up. The subjects were taking glutamine, an inactive amino acid or pure placebo prior to the exercise testing session. One would expect that the second set of repping to failure would produce less total reps than any earlier set of the same load. In this study when examining the raw data, those who received the glutamine experienced the least reduction in leg press performance, while not doing especially different than the other groups in the bench press aspects of the study. From this we can gather that perhaps taking the glutamine one-hour prior to training and only on one day may not be totally conducive to whole body performance benefit, but it does aid in the major muscle groups getting some protection against the decline in exercise performance. While it is preliminary, this is one reason to include glutamine in your arsenal.

Over Exercise? Get Sick?
Have you ever had a stretch of time that you were training hard, beyond hard even and doing this over consecutive days or weeks? Some people reach such a state after a while of this type of training (with no real recovery time for neural or muscular recovery) and they become stale and even stagnant in the gym. Shortly thereafter, this state of over-reaching becomes official over-training. Being in a state of overtraining will lead the immune system to become depressed and to function sub-optimally. Do you want to know the amino acid that takes the biggest hit when you over-train? Glutamine. Suppressed or sub-optimal plasma and intracellular glutamine levels are a result of too much training. These sub-par levels actually correlate well with the increased occurrence of upper-respiratory infections (chest/head colds). Now, since we are all forward thinkers here, it is time to realize that training more does not always equate into bigger or even stronger muscles. In fact, train too much and do so without proper recovery and nutrition and you are training yourself to not look like someone who works out. Kinda sucks, right? All that effort put into training and your body does not respond. It is during the stage where you are either over-trained, getting on your way to this state or even if you live in a hypoxic area (high altitude) that the conditionally essential amino acid glutamine is lost. Recall that glutamine is needed for lymphocyte proliferation and macrophage phagocytosis. Thus if glutamine levels in the body are too low, then your defense against opportunistic infections is greatly reduced.

From the above, do you think that anyone who trains hard and does so on an almost daily frequency would need or should think about supplementing with glutamine? I do. Meaning that if you help your body maintain its normal homeostatic amount of circulating and "stored" glutamine, perhaps you will help strengthen the immune system by fortifying it with the nutrition that your immune system needs (it also needs protein, vitamins, Thione-- and other key factors for ancillary support). Glutamine also is important for reducing pro-inflammatory cytokines, improving how the gut (intestines) absorbs other nutrients and, in fact, can reduce mortality from major illnesses. Some people advocate taking up to 30 grams of glutamine per day and data from the clinical nutrition world appears to support these recommendations.

Buy Glutamine Glutamine increases overall nutrition
We have all seen the television commercials that tell how certain sports drinks (known as glucose-electrolyte solutions) can replenish what you lose during exercise. What these commercials have not told you is that there is a better drink that is not being sold. If you could improve upon the most popular sports drink (it generates about $1 billion per year in sales) what would you do? Did you know that when athletes train long and hard that their intestines can temporarily have a reduced capacity to absorb certain types of nutrition and that diarrhea can occur? This happens mostly to runners who run longer than an hour. In addition, athletes and non-athletes do get ill and sometimes this type of illness requires that fluid be put back in. The fact is that if you add glutamine to these glucose-electrolyte drinks (oral rehydration solutions) than it will stimulate the body to absorb more of the water and other nutrients that are in the drink. Dehydrated muscle looks flat, well hydrated muscles look full. Glutamine may just be what people most overlook when wanting to have the appearance of a well-developed body. For this reason, if you are a carbohydrate or sport-drink type of athlete (especially during the post-exercise time period), it is time for you to think about adding 10 grams or so of glutamine to that drink. Over the long run, your body will thank and adore you for it. So might those who see you outside of the gym.

The evidence is clear that including 10 to 30 grams of glutamine per day, especially during times of hard or excessive training, can help the body not get sick, contribute towards fuller muscles, enhance nutrient absorption and support the immune system. For these reasons, one would have to wonder why more people are not aware of the benefits of glutamine. Do not expect that glutamine will immediately aid your efforts in the gym or improve your body overnight, but consistent smart use of this amino acid can pay off big time.

Douglas S. Kalman MS, RD is a Director in the Nutrition and Endocrinology Department of Miami Research Associates ( and contributes to the ProSource Forum.