Glutamine is an important immune enhancer even for people who don't exercise. Numerous studies have shown that glutamine is particularly important after a stressful or traumatic event such as surgery. Another one of glutamine's many benefits is that it enhances the storage of muscle glycogen. Glutamine can have what is referred to as an antiproteolytic affect in skeletal muscle because it prevents protein breakdown. Glutamine is also known as a cell volumizer.
Clinical studies show that glutamine infusion helps maintain muscle mass in critically ill patients.
If the amount of glutamine in your diet is insufficent then your body will borrow needed glutamine from skeletal muscle. As you can see, Glutamine is crucial to the human body, especially in the skeletal muscles and immune system. It is an excitatory amino acid due to its role as a neurotransmitter. Glutamic acid is a very polar molecule usually found outside of proteins and enzymes. Glutamic acid is easily converted from glutamine but it was not isolated from protein until 1932.