Glutamine is an anti-catabolic agent which means that it can help to promote new muscle tissue growth. Glutamine has also been shown to have a positive effect on the immune system, which gets weakened during intensive training. Additionally, if you’re a competitor and dieting, it can provide a boost to your immune system during times of caloric restriction. Glutamine is a conditionally an essential amino acid, one which all athletes should add to their gym bag.