Errani, Schiavone, Stosur are definately using some stuff on the womens side.
On the ATP Tour there are quite a few suspicious ones as well.
As for Djokovic.
The guy used to have a gazillion allergies and intolerances until 2009/2010.
- Allergic rhinitis
- Roasting in the sun like a turkey
- several torn muscles
- gluten intolerance
- and and and
From 2005-2009 he was a retirement Queen, quitting like crazy due to ridiculous injuries.
The guy could barely last a fifth set match when things weren't going his way.
Now since 2011 he plays one marathon match after the other and during the post match interview he looks like he can last another 5-6 hours on court.
Seriously such an immense change can't be explained with a healthier lifestyle and ****.
All of the TOP guys might be taking some crap, but Novak takes the cake for me when it comes to a "who would you mention first" question.