This document discusses the history and science of drug testing in sports. It provides background on the types of performance enhancing drugs used by athletes and their effects. It then describes the anti-doping agencies and rules established to regulate drug use in sports. The document outlines the banned substances and methods according to their classifications. It details the sample collection and testing process, including the analytical methods used to detect drugs in urine and blood samples. Finally, it mentions some notable doping cases that have occurred in sports over time.