David Rudisha's coach says they are looking for an "extra edge."
The repeat gold medalist is adamant that he's clean.
The still unpublished results of a 2011 athlete survey are very telling.
The double-Olympic medalist's coach dismisses the doubters.
A handy reference guide for runners.
Former USATF CEO wants to give up the fight against doping.
Russian Natalia Volgina may be stripped of her Old Mutual Two Oceans Marathon title.
Alptekin's Turkish countrywoman Nevin Yanit is also suspected of cheating.
He did it thanks to a technicality.
One is a London Olympics silver medalist.