What it Supports- Glutamine's ability to preserve skeletal muscle mass in times of stress is perhaps its best known quality.  There is essential for the prevention of muscle wasting.  Intense exercise training results in a well-described drop in plasma glutamine levels. Chronically low glutamine levels have been implicated as a possible contributing factor in athletic overtraining syndrome as well as the transient immuno-suppression and increased risk of infections that typically affects competitive athletes during intense training and competition.

How It Works- Just like the multi-talented decathlete, glutamine is a multi-faceted supplement.  Glutamine helps regulate muscle mass, is involved in immune system support, affects the synthesis of glucose and may even improve insulin metabolism.  At the molecular level, glutamine exerts its effect by preventing the loss of a specific protein called myosin heavy chain (MHC).  The MHC protein determines the contractile properties of a muscle fiber.  The fast form of MHC results in fast twitch fibers and the slow version of MHC results in slow twitch fibers.  Retention of this critical protein is closely linked to glutamine abundance thus strengthening the support for glutamine supplementation.

Whole Food Sources-

Dietary sources of glutamine include beef, chicken, fish, eggs, milk, yoghurt, certain cheeses, dairy products, cabbage, beets, beans, spinach, and parsley. Small amounts of free L-glutamine are also found in vegetable juices and fermented foods, such as miso.[1]