The use of substances to enhance performance in sport--what we call \u201cdoping\u201d today--is as old as sport itself.\xa0 In Episode I, we introduced the current anti-doping crisis in sport.\xa0 Today, we search for the origins of the anti-doping movement to understand how we got here.\xa0 This is Episode II in our six-part series: \u201cThe Anti-Doping Crisis in Sport.\u201d