you will never have a fair competition because all people are born different - people have differing testosterone levels, differing body builds, differing muscles mass, etc. most competitive sports are plagued with doping because hard work only takes you so far before your body hits its limit.
just let the olympics and shit be a showcase and celebration of what humans can accomplish, fuck it make doping legal as well, i wanna see how wild humans can get
not to mention the time/money it takes to train. privileged folks can spend heaps of time/money training if their upbringing is secure.
Also, the training some children are put through at such young ages often crosses the line to outright child abuse.