'And she's angry and just not nice, to be honest. I'm only that person for three hours a day when I'm on the court. The rest of the time I'm just Serena. I'm the class clown.' Today Williams is the oldest player in history to be ranked world number one.
Early in 2011 she was hospitalised with a blood clot in her lungs, which nearly killed her. She tells Fitness that for the first time she realised her health came first.
