L-arginine supplements may enhance exercise performance by increasing nitric oxide in the body, which improves blood flow and oxygenation to muscles. It promotes athlete performance enhancement, many athletes use L-arginine for pre-workout energy. It can increase growth hormone response, and so can increase muscle mass. Also, it has an impact on insulin, which is another anabolic hormone. Supplementing with l-arginine allows your body to use accumulated fats as a source of energy. The accumulated fat is burnt to produce energy and to aid in muscle mass formation and development. L-arginine thus boosts your body metabolism as well as forms building blocks for muscle formation. L-arginine supplements are taken by many populations, including athletes and those who have certain medical conditions like high blood pressure, for a variety of reasons.