just what they are called: substances that are used for enhancing performance. The use of these substances is of particular concern to agencies that govern sports, especially amateur sports. Some examples of performance enhancers that are used are anabolic steroids, stimulants, diuretics, and other alternatives. Steroids are chemicals that are typically produced by the human body as a way to regulate various bodily functions. Anabolic versions are used to increase muscle mass and endurance.