How do performance-enhancing drugs deprive non-users of thier victories?

This question seems pretty straight forward.

Athletics is about pushing the body to its limits to take on other athletes, nature, or some other physical obstacle. Genetics plays a part in this competition but that’s considered fair play. By taking performance enhancing drugs an athlete is giving himself or herself an unfair advantage. They’re pushing their bodies beyond their own natural limits by artificially adding strength and endurance, and in doing so they put other athletes at a clear disadvantage.