In most cases maybe. Lance Armstrong would probably disagree as he is being pursued by sponsors for sponsorship money to be returned, event mgt for event winnings etc etc

Its a dangerous game, without thinking about health impacts

Indeed. I was talking more specifically about athletics, but you're right on Armstrong. Hopefully seeing what's happening to him will act as an even bigger deterrent for those thinking about cheating.

I wonder just how many sportstars are actually totally 'clean' and perform with absolutely no enhancement supplements or additives or allowed 'medications', and rely wholly on exercise and a regular planned (actual food based) diet ?

Unless you are taking banned substances then you are, by definition, "clean". I don't see what adding "supplements" or "additives" into the mix is relevant. All food you consume is a long list of individual substances and additives, and a "supplement" is just an extra portion of something you already consume. Would Popeye fall foul of something for his spinach supplements? He would clearly not hae won as many fights as he did had he been totally spinach-free.

It just means that there's always that fine line between those substances and medications that are legal and those that aren't, noting both are designed to give an additional enhancement to natural performance.

Some people stray over that line due to poor choices or bad advice, others don't but gain unnatural advantages through things other than just hard work and training too.

There's way too much money in sport to suggest that people won't bend/exploit the rules to give them the maximum, albeit allowable, advantage, whether a doctor signing off a TUE or those drugs which might not be detected or aren't yet on the banned list.

Its not as clear cut as some cheat and some don't, just that some are better at avoiding falling foul of the rules, whether through morales or money is debatable.