Actually what the Ruskys did is one of the oldest cheats in athletics. They probably felt that testing for drugs was so focused they could get away with an oldie that no one checks for much today.

The proceedure used is called blood doping! It is a simple way of boosting oxygen levels sky-high and thus delaying the build up of lactic acids. This gives an extended endurance before fatigue diminishes performance.. Often the difference between a medal and not finishing.

They way it works is simple; you remove some of the athletes own blood on wed. and re-inject it for friday's distance event. Hard to detect--no drugs just a longer period before a catabolic reaction.

This was common for endurance events in the sixties, haven't heard of it lately, until this set of games.