Earlier this month the 11th annual CrossFit Games took place in the US. While the event has come a long way from humble beginnings, the prizemoney and fame now attached to it have led to concerns that competitors may be doping to gain an unfair advantage. CrossFit is a fitness regime practised by people all around the world. But the majority of those who take part in its high-intensity competitive workouts are not elite athletes: they do so on an amateur level or recreationally.