Supports Nitric Oxide Arginine is a conditionally essential amino acid & a precursor to Nitric Oxide (NO). This means Arginine is essential in the bodily process of creating nitric oxide. Nitric oxide is responsible for dilating blood vessels, which increases overall blood flow, and improves cardiovascular health. For athletes, the body uses Arginine faster than it can produce, leading to losses in performance. Without Nitric Oxide = Constricted blood flow With Nitric Oxide = Enhanced blood flow