Arginine, as a precursor to nitric oxide, dilates blood vessels leading to great pumps, vascularity, and it may increase oxygen levels to the heart and other mus cles. It can also improve penile erections. Athle tes benefit from a boost in exercise capacity and increased blood flow. More nutrients will reach the muscles and the fatigue by-products will be flushed out faster and more efficiently resulting in better recovery and more gains. Arginine may increase the healing process of muscle tissue micro-injuries, and it may have a beneficial impact on natural growth hormone production, insulin output and sensitivity.