World No. 1 Novak Djokovic will not reveal what goes into what he calls his secret recovery program that his team has developed for him, but says it's all on the up and up. Djokovic needed more than five hours to outduel Stanislas Wawrinka in a fourth-round match that ended at 1:43 AM Monday, and then came back at 7:30 PM Tuesday to beat Tomas Berdych 6-1, 4-6, 6-1, 6-4 in two hours and 31 minutes in the Australian Open quarterfinals.

“The people who don't know tennis, who have never been in those kinds of situations would not truly understand what the player has to go through, not just when you prepare for a Grand Slam, but also during a Grand Slam,” Djokovic said. "After five hours of match, you need to really put a lot of time into recovery, different kind of recoveries. I understand that many people have many different views and opinions, and I respect that. But I'm doing everything that is legal, that is correct, that is natural that I can, possibly can in my power, and it's working well.”