L-arginine is best when used with Intensive cardiovascular exercises, recommends Runners World, which claims that it improves endurance. However, limited studies have shown the positive effects of l-arginine on exercise performance when used alone.
Due to the limited research isolating l-arginine for exercise improvement, the studies isolating l-arginine are not adequate to provide a substantive answer as to whether it is actually effective for athletes, as the Mayo Clinic notes. Since it is a natural supplement found in foods such as milk, eggs and nuts, athletes who consume l-arginine rarely experience adverse reactions, according to Drugs.com.
Some evidence shows consuming 6 grams of the supplement one to two hours before exercising can increase endurance, as WebMD reports. Other studies have shown that taking the supplement did not result in improved performance for male cyclists.
Despite the inconsistent evidence surrounding l-arginine as an athletic supplement, it remains a popular supplement for athletes and bodybuilders. L-arginine has a similar effect as beet juice, claims Runners World, and it has been known to improve endurance by about 1 to 2 percent on a fixed-distance race. AN enzyme converts l-arginine to nitric acid, so provides the same effects as beet juice – dilating blood vessels and lowering blood pressure – thus allowing for a more effective workout.