The role of anabolic steroids plays several important roles. The first would be to maintain and even increase muscle mass. Lean muscle production is one of the most important requirements in maintaining good physical health. The more lean muscle mass one has, the more efficient their body is as a calorie-burning machine, as muscle consumes more calories than fat does. A secondary role would be to maintain sexual characteristics that are associated with that sex, such as deep voices for men, menstrual cycle for women. A third important role would be the maintenance of sexual libido, or desire, which would be important in propagating the species (having children or offspring).
The use of artificial anabolic steroids has placed somewhat of a "black eye" on the sports industry, with athletes participating in steroid usage in an attempt to build up their natural physical builds. Sports in college and high school maintain strict requirements about the usage of anabolic steroids by requiring athletes to submit to "doping" tests, designed to detect steroid usage, among other drugs.