Glutamine is the most abundant amino acid in the body, making up over 50% of the free amino acids in muscle. Most of the glutamine in our body can be found in the muscle, with smaller amounts in organs such as the liver, lungs, brain, and blood.

While glutamine plays a role in fuel utilization for the small intestines and immune system, it also plays key roles in muscle protein synthesis and muscle recovery. For athletes and lifters, glutamine is indeed important, especially for those pushing their bodies to the limit and challenging the boundaries of human performance.


Glutamine plays a key role in immune function and the body’s ability to moderate cortisol, also known as the stress hormone. Although it’s healthy and natural when in line with the body’s circadian rhythm or sleep/wake cycle, cortisol can cause problems when chronically or constantly elevated. This can lead to illness, muscle catabolism or breakdown, and fat storage.

Glutamine can help an athlete handle training stress and immune health, which is key if you want to constantly push your body. The better you can recover or handle the physical stress of training, the more volume and intensity you can handle. It also allows you to train more often at a high rate or with greater performance. 


In addition to glutamine’s key role and indirect function in immune health, it may help you grow muscle or strength through more direct pathways, like muscle protein synthesis and post-workout recovery.

Supplemental glutamine may reduce muscle protein breakdown by increasing intracellular (within the muscle cell) concentrations and by reducing the turnover of mRNA, a transcription factor that may lower your total protein balance or nitrogen balance. In short, it can reduce protein turnover or degradation, which improves protein balance and muscle retention. Remember – long-term muscle is based on two EQUAL factors:

  1. Increasing protein synthesis and new protein to make muscle
  2. Decreasing protein breakdown and the breakdown of existing muscle

Supplemental glutamine may also reduce glutamine’s relocation from the muscle for other functions. For example, glutamine is used by many processes in the body. On occasions, the small intestines or immune cells may require additional glutamine, at which point the body may remove glutamine stored in the muscle. By providing an abundance of external supplemental glutamine you can ensure the body always has adequate stores (Antonio and Street, 1999).

Glutamine may also spare leucine, the key anabolic protein responsible for stimulating muscle protein synthesis. Hankard et al., (1996) found intravenous infusions of glutamine helped spare leucine oxidation or use. Other research by Boelens et al., (2001) found glutamine may reduce muscle catabolism or atrophy (wasting).

Other research by Dahl et al., (1996) stipulated that glutamine studied in rats may increase cell osmolality, which can increase cell swelling and volume. Recent research by hypertrophy expert Brad Schoenfeld highlighted this as one of the three key mechanisms behind muscle growth which may support this theory.

Direct research by Hakimi et al., (2012) found significant improvements when adding glutamine supplementation into a weight training program. The previously untrained participants showed significantly greater increases in upper and lower body strength, explosive muscular power, testosterone levels, Growth Hormone, and IGF-1 along with lower cortisol concentrations levels.

Fermented Glutamine

Most commercially available glutamine is sourced from animal fur or even human hair. Kaged Muscle Glutamine is 100% plant-based, produced using a unique fermentation process for a clean, effective choice. It's vegan, non-GMO, free from banned substances. Always look at the quality of a product, not just the price. Buying fermented glutamine is a superior choice for long term supplementation use.


As you can see, glutamine may be key for athletes and bodybuilders. Although we still need a lot more research into this area, the mechanisms of action and current research are supportive. If you want to add glutamine into your regime make sure you are usingRE-KAGED® post-workout and adding in extraKAGED MUSCLE L-glutamine to at least one other meal per day. In terms of dosing, around 10 – 20g per day is sufficient, depending on body size.

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