Have you ever just stopped for a minute to think about what supplement ingredients are the biggest waste of time and money?
Perhaps you don’t spend your waking hours with ideas like this, and instead focus your time and effort into finding supplement ingredients that are the biggest bang for your buck. As a kinesiologist and sports nutritionist, I have to take the time to think about both ends of the spectrum; what supplement ingredients are actually effective and should be promoted on the market, and what supplement ingredients are completely ineffective and should be removed from the market altogether.
For as long as I can remember, I’ve seen athletes and supplement companies represent Glutamine as if it is the most important supplement ingredient ever created. If all you do is take a quick glance at the scientific theory and an even shorter glance at actual published data, then it is easy to see why Glutamine has been a staple in the supplement industry for so long.
A quick Google search will show you that Glutamine has profound effects on your body because the immune system cells and the cells of your intestine feed directly off of Glutamine, it increases cellular hydration and glucose uptake, and it can even reduce the breakdown rate of Leucine which equates to massive GAINZ!
The only issue with this is that the overarching majority of studies that show Glutamine to be an effective supplement are in vitro studies. In vitro means “within the glass,” and is a type of study that takes place outside of the living organism (the human body, in this case).
In vivo, on the other hand, means “within the living” and is a type of study that requires taking measurements directly from within the living organism you are studying. So, in other words, the general research shows that Glutamine supplements could be very effective for increasing muscle mass, strength, and many other athletic and health variables, but only in a petri dish.
The research behind glutamine isn’t sound considering athletes actually taking the supplement
So when you add Glutamine to a test tube that contains muscle fibers, there is an increase in the synthesis of new muscle protein within those muscle cells, but when you replicate that same level and concentration of Glutamine in an active, healthy individual, there is no significant change in muscle growth, strength, or immune function response. Keep in mind that the operative phrase is “active, healthy individual.”
The most profound and significant study on the actual affects of Glutamine supplementation on muscle performance, body composition, and muscle protein breakdown was conducted way back in 2001. This is the study that supplement companies who use Glutamine either do not want you to know about, or they themselves are ignorant of. Either way, it is information that you need to know before you decide to pull the trigger on buying this supplement ingredient.
Thirty-one subjects, including both males and females between the ages of 18-24, were randomly assigned to one of two groups. The first group supplemented with Glutamine while the second group supplemented with the equivalent amount of maltodextrin placebo. After six weeks of total body resistance training using 4-5 sets of 6-12 reps at intensities between 60-90 percent of the subjects 1 rep max, there was no significant difference between either group on 1 rep max bench press, 1 rep max squat, peak knee extension torque, body composition using a DEXA Scan, and muscle protein breakdown via 3-methylhystidine in the subjects urine. Due to these results, the researchers concluded “…glutamine supplementation during resistance training has no significant effect on muscle performance, body composition or muscle protein degradation in healthy young adults.”
There were no significant differences between glutamine supplementing and placebo groups in strength, body composition and muscle physiology measures.
So that’s it. Glutamine, in general and based on the data we have right now, is not worth your time or money…unless you fit into a very unique category of athletes who do not get enough Glutamine from their diet or participate in activities that chronically deplete their natural Glutamine concentrations in plasma. Like most vitamin and mineral supplements, a benefit is typically only shown if there was first a deficiency related to that specific vitamin or mineral. The same is true for Glutamine. Individuals who tend to have lower levels of Glutamine, or perhaps a real Glutamine deficiency, may improve markers of health, wellness, and even some athletic measures after Glutamine supplementation is added. So are you at risk of being Glutamine deficient?
If you eat a vegan, vegetarian, or low-dairy diet, you risk having a Glutamine deficiency, since the major source of glutamine in the human diet comes from animal source protein. So, if you do not typically eat a diet high in animal source protein, then supplementing with Glutamine may aid with increasing muscle protein synthesis, glycogen replenishment, and boosting your immune function.
Perhaps the only other time Glutamine supplementation may actually provide some health, performance, or recovery benefit comes down to whether or not a specific activity has the effect of reducing normal levels of Glutamine within blood plasma. Since high intensity activity like most sports and resistance training do not deplete your body’s Glutamine concentration, supplementing with Glutamine tends to have no real benefit. Ultra-endurance exercise (continuous in nature and lasting over 2 hours), on the other hand, has been well documented to decrease Glutamine levels. This effect has serious performance and recovery implications for the ultra-endurance athlete since exercise-induced immunosuppression is such an epidemic with endurance athletics. For this specific population, supplementing with Glutamine, or simply adding more protein to their diet, specifically before long bouts of training, has been shown to offset the drop in plasma Glutamine levels, and thus promotes normal neuromuscular metabolism and immune function.
Conclusion
So there it is, folks. There are very few instances when Glutamine should even be considered as a way to improve performance or health. It simply is not anything close to what the current market influencers want you to believe. Unfortunately for them, you now have the facts, and can make your own choice on the matter. At the end of the day, if you eat enough protein, then there is just no need for Glutamine.
Maximizing your training and adaptation is much more dependent on hitting your daily caloric goal and maximizing the effects of protein, carbs, and fat by hitting your target macronutrient goals. On top of that, get good rest and minimize total stress. Keep the main thing, the main thing, and don’t fall for the flashy marketing and over the top supplement claims, especially those about Glutamine!
References
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;86(2):142-9.
Examine.com. “Glutamine – Scientific Review on Usage, Dosage, Side Effects.” Examine.com, Examine.com, 9 July 2017, examine.com/supplements/glutamine/.
About Kevin Kuhn
Kevin Kuhn, M.S.Ed., CSCS, MFS is a Kinesiologist and Sport Nutrition Coach in Dallas, Texas. Before moving to Dallas in 2012, Kevin was the head strength & conditioning coach for the Indiana Invaders professional running club in Indianapolis, Indiana. Kevin specializes in athletic performance with great interest and experience in running-specific strength & conditioning, corrective exercise, and exercise and sport nutrition. Kevin has been certified by the National Strength & Conditioning Association as a Certified Strength and Conditioning Specialist (CSCS) and as a Master Fitness Specialist by the Cooper Institute.
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