Supplementing with glutamine enhances muscle glycogen synthesis.
by Paul Cribb, B.H.Sci HMS
Muscle glycogen is the storage form carbohydrate and the primary fuel of intense exercise. For bodybuilders, glycogen-full muscles mean a greater work capacity, faster recovery and muscle growth. Many bodybuilders restrict their carbohydrate intake in an effort to remain lean, this can create low muscle glycogen levels that limit recovery and the ability to train intensely. This study demonstrated that taking glutamine straight after training stimulates glycogen synthesis in muscles and appears just as effective at restoring glycogen levels as a high-dose of carbohydrates.
The participants in this study completed three glycogen-depleting weight training sessions. After each session they received one of three different drinks (by a systemic rotation), a carbohydrate solution (61-grams), a glutamine solution (8-grams), or a combination of both. The muscle biopsy results revealed that 8 grams of glutamine was as effective as 61-grams of glucose for restoring muscle glycogen levels, while the combination of glucose and glutamine restored whole body glycogen levels more effectively than either supplement taken separately.
These findings are fantastic for competitive bodybuilders, wrestlers, and other athletes that may restrict carbohydrate intake yet require high muscle glycogen levels for optimal performance. These results also have important implications for those that follow a low-carb diet. Taking an 8-gram serving of glutamine after exercise will restore muscle glycogen levels as effectively as a high dose of glucose. This means bodybuilders and other athletes can replenish vital muscle glycogen levels with minimal amounts of carbohydrates! Pre-contest bodybuilders can use glutamine in their carb loading phase to enhance muscle glycogen accumulation.
Bodybuilders and other strength athletes should aim for rapid replenishment of muscle glycogen stores straight after exercise. By adding glutamine to your post-workout meals you will enhance the replenishment of vital muscle glycogen and whole body energy stores.
This research demonstrates more important benefits of glutamine supplementation for athletes. Glutamine remains one of the most underrated, research-proven performance enhancing supplements an athlete can use.
J.Appl.Physiol.86;6:1770-1777, 1999.