Citrulline is an Amino Acid. Citrulline is shown to increase arginine in the blood leading to greater NO which means increased blood flow. This allows greater endurance during a workout. Malate gives citrulline stability, but it is also known to have anti-fatigue properties. Thus, Citrulline Malate goes a long way to increase vascularity and longevity, and by default, aids in recovery as well.