The Olympic games was originally a competition for amateur athletes. Professional athletes were said to have an unfair advantage, since they could afford to spend most of their time training. It wasn't until the 1970s until this limitation was officially dropped.
But is the playing field necessarily level? Genes can make or break an athlete in many competitions.
In general, Olympic athletes tend to be genetic freaks who have managed to put themselves through brutal training regimes and taking anything considered to be performance-enhancing, but not explicitly banned and having the luck not to become injured.
Athletes that choose not to push the limits in these areas are not competitive.
But why not let athletes push all the limits? It would be more exciting if they were permitted to take performance enhancing drugs.
I also wonder what will happen in the future when we have more advanced medical technology that could allow us to effectively rebuild our body, perhaps on a molecular level. Or use genetic engineering to engineer athletes from the ground up. A superhuman Olympics?
Or are these sorts of ideas destined only for the circus?