not all athletes use you fool.
Is this like the god position? You say something and it remains true until proven otherwise? This is argumenting from not-knowing (ignorance).
If you have no idea, just like us, what professionals use, then do not make a statement being 100% sure of anything. Goes for everybody.
We can only look at the situation and reasonably guess
the questionmark based on surrounding evidence
. The surrounding evidence is that most if not ALL professional sportsmen use PED's. Therefore a logical step would be to say 'I think most if not all professional sportspeople use PED's, BUT
without sufficient knowledge I cannot be certain of this'.
Where there is money, history has shown that people dependent of that money (sportsmen in this case) will cheat and lie to get ahead. Therefore the preliminary assumption would be to say most use, other then most dont use