The world of international sport is big business, driven by an increasing pressure to be the fastest and biggest in any field.
And as the stakes go up, so do the number of allegations of doping.
The most recent involves a British doctor who allegedly prescribed performance-enhancing drugs to more than 150 athletes, according to a Sunday Times investigative report.
Premier League footballers, Tour de France cyclists, and international tennis players are among those accused, and several have denied the report.
But to many, these allegations come as no surprise.
So what is the point of international competitions if so many participants are determined to cheat?
Presenter: Martine Dennis
Lea Cleret - Head of Research Policy and Education at the International Centre for Sports Security.
Kelly Holmes - Two-times Olympic gold medallist.
Philip Barker - Olympic historian and journalist.
Source: Al Jazeera