More than 100 athletes have been banned from competing in the London Olympics because of doping suspensions. Doping allegations have become common in many sports, most notably in cycling, baseball, and track and field. Dr. Dennis Cardone, associate professor of sports medicine at NYU Langone’s Center for Musculoskeletal Care, and Dr. Gary Wadler, clinical associate professor in the Department of medicine at Hofstra University, explain how performance-enhancing drugs work, how they're detected, and how doping has been addressed in sports. Dr. Wadler served as the Chairman of the World Anti-Doping Agency's (WADA) Prohibited List and Methods Sub-Committee and serves as an ex-officio member of WADA’s Health, Medicine, and Research Committee. He is the lead author of the textbook Drugs and the Athlete.