I thought the original Olympics were a religious festival which grew. The first day of the festival was devoted to sacrifices to the gods, as was the last day.
And the winners were awarded a branch of wild olive, although the winners from some states were given tax-free status, allowed to live free in special halls set aside for distinguished people, or given cash prizes.
There are a lot of parents out there who DON'T give their children the choices. Ballet mothers, football fathers. And there are programs out there to identify early potential in littlies and whether they want to or not - they child is in.
Most Olympic sports have selection processes that attempt to identify future champions and initiate specialized training---often before the prospect finishes elementary school. The lure of a college scholarship or a professional career can also motivate athletes (and their parents) to commit to specialized training regimens at an early age. The low probability of reaching these lofty goals does not appear to discourage many aspirants.
To be competitive at a high level requires training regimens for children that could be considered extreme even for adults. The ever-increasing requirements for success creates a constant pressure for athletes to train longer, harder, more intelligently, and, in some cases, at an earlier age. The unending efforts to outdo predecessors and outperform contemporaries are the nature of competitive sports. The necessary commitment and intensity of training raises concerns about the sensibility and safety of high-level athletics for any young person.