how does an athlete get to participate in the olympic games
All professional athletes are eligible for the Olympics, subject to the approval of the IFs.
Olympic Games
 After the 1988 Games, the IOC decided to make all professional athletes eligible for the Olympics, subject to the approval of the IFs.
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Olympic Games [SEP] Amateurism and professionalism
The advent of the state-sponsored "full-time amateur athlete" of the Eastern Bloc countries further eroded the ideology of the pure amateur, as it put the self-financed amateurs of the Western countries at a disadvantage. Beginning in the 1970s, amateurism requirements were gradually phased out of the Olympic Charter. After the 1988 Games, the IOC decided to make all professional athletes eligible for the Olympics, subject to the approval of the IFs.