03:05HARDtalkDirector General of the World Anti-Doping Agency - David HowmanBBC World Service Duration: 23 minutes Fri 24th Jul 2015, 03:05 on BBC World Service OnlineAvailable for over a yearListen nowWhy is it proving so hard to root drugs out of sport? Show more GenresNewsFormatsMagazines & ReviewsBrandHARDtalk Source: BBC Online