The IOC plans to carry out 2,453 tests in Sochi, including 1,269 pre-competition controls. That's a 57 percent increase in pre-games tests from the 2010 Winter Games in Vancouver.
The majority of the 1,184 in-competition tests will be done in sports like cross-country skiing and biathlon, endurance events with a history of blood doping and EPO use. About 20 percent of the doping controls will be blood tests.
Much of the testing will be based on intelligence gathered from law-enforcement agencies, whistle-blowers and previous suspicious blood level results.
The testing program begins on Jan. 30, the day the athletes village opens. From then until the close of the games on Feb. 23, Olympic athletes can be tested at any time and at any place, including training sites anywhere in the world. The games open on Feb. 7.
About 2,000 of the 3,000 athletes competing in Sochi are expected to be tested — some of them two, three or even four times. The top five in all medal events are tested, as well as others chosen at random.
Since testing began at the Winter Olympics in 1968, only 20 doping cases have been reported by the IOC. Only one was reported at the 2010 Vancouver Games, with Polish cross-country skier Kornelia Marek disqualified after testing positive for EPO. Two hockey players were reprimanded for minor violations after testing positive for stimulants.
There was one positive test during the 2006 Turin Games, with Russian biathlete Olga Pyleva stripped of a silver medal.
However, there was a wider doping scandal in Turin. Acting on a tipoff from the IOC, Italian police raided the lodgings of the Austrian cross-country and biathlon team, seizing blood doping equipment. While no Austrians tested positive at the time, four later received life bans from the IOC.
The IOC freezes and stores Olympic samples for eight years at the lab in Lausanne, Switzerland. The samples can be retested when new methods become available. The storage period will be extended to 10 years starting in 2016.