Supplements 101: What is Glutamine?

What is Glutamine? 

Glutamine (aka:  L-Glutamine) is a naturally occurring non-essential amino acid commonly stored in muscles and released into the blood stream during times of stress.  It is used by the immune system during times of stress such as physical trauma, burns, starvation, and during prolonged and intense exercise.

Glutamine as a Super-Recovery Nutrient

No athlete wants to be sidelined from their sport due to a cold, especially when the sport could be the cause of the cold!  There is evidence too much intense exercise, such as repetitive long distance running, marathon training, or triathlon training, can reduce immunity.  Intense exercise also lowers blood levels of glutamine, which can remain persistently low with overtraining.¹ 

Overtraining syndrome is when an athlete is training vigorously, yet performance deteriorates.  One sign of overtraining syndrome is a suppressed immune function, with an increased incidence of upper respiratory tract infections.  An increase incidence in these infections is also associated with high volume and/or high intensity training, as well as with excessive exercise, such as marathon or triathlon training.  The upper respiratory tract infection normally manifests between 3 to 72 hours post-race.²

Glutamine is shown to have restorative effects and during times of stress, glutamine needs increase.  The effects of glutamine supplementation on immune function after exercise have been inconsistent,^{3, 4} but a double-blind trial giving athletes glutamine (5 grams after intense, prolonged exercise, then again two hours later) reported 81% having no subsequent infection compared with 49% in the placebo group.⁵

Have You Gotten Sick After Intense Endurance Exercise?

In Health and Happiness,

Kelly Harrington, MS, RD

Registered Dietitian Nutritionist for Healthy Goods

References:

1. Rowbottom DG, Keast D, Morton AR. The emerging role of glutamine as an indicator of exercise stress and overtraining. Sports Med 1996;21:80–97 [review].

2.  Lakier Smith L.  Overtraining, excessive exercise, and altered immunity:  is this a T helper-1 versus T helper-2 lymphocyte response?  Sports Med. 2003;33(5):347-64.

3. Rohde T, MacLean DA, Pedersen BK. Effect of glutamine supplementation on changes in the immune system induced by repeated exercise. Med Sci Sports Exerc 1998;30:856–62.

4. Castell LM, Newsholme EA. Glutamine and the effects of exhaustive exercise upon the immune response. Can J Physiol Pharmacol 1998;76:524–32 [review].

5. Castell LM, Poortmans JR, Newsholme EA. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol 1996;73:488–90.

Natural Products Foundation:  Glutamine