Glutamine is the most common amino acid found in your muscles. It is the main transporter of nitrogen into your muscle cells. Glutamine levels are depleted during exercise which decreases strength, stamina and recovery. Taking L-Glutamine supplementation has been shown that it can help the lower the risk of breakdown of muscle and improving protein metabolism. L- Glutamine is best taken when ‘cutting down’ to improve protein synthesis and reduce the risk of muscle breakdown.