Before everyone dives head first into the rabbit hole, to be fair the physical and mental conditioning of footballers was revolutionised in the early 2000s.
In the UK, Wenger is often labelled as one of the catalysts but obviously it's not him alone. For players, alcohol has been heavily diminished as has smoking.
They eat far better (a friend of mine is a club chef and it's rigorous), training has improved and they are heavily monitored in terms of their physical condition.
The game's less physical too, before discussing how their mentalities are supported. All that alone means players are now in better shape to play regularly.
However, I'm not saying that performance enhancing substances aren't a part of it too, but rather I do not believe it's that alone - a small part for the elite.
Let's be honest, there's enough footballers who've inhaled powders up their nose and not been caught, so they'll get around non-illicit drugs.