All good things must come to an end, but the great ones can extend their careers beyond the norm.

A resurgent Roger Federer has shown no signs of slowing down capturing six titles this season, including two of the four Grand Slam tournaments.

Federer: Winning WTF is Goal

The 36-year-old Swiss is not thinking about retirement, but realizes it's inevitable for athletes.

The second-ranked Federer said as long as he continues to meet four personal requirements—health, family fulfillment, sustained success and ongoing enjoyment of traveling the world—he will continue to play on the pro circuit.

“I know it (retirement) is sooner or later. I know I’m not 22 anymore, but I don’t have a date,” Federer said told Xinhua in comments published by Gulf News. “If the body allows me to play, my family allows me to play, if the success is still there, if I’m happy to travel, I will continue. But the four things have to work, if one of the four doesn’t work, it maybe the time to stop. But for now, it’s ok.”

Federer and wife Mirka are the parents of two sets of twins. The father of four said spending time with his family and ensuring adequate rest and recovery are essential to keep his competitive fire burning.

"For me, I have come to realize that sometimes less is more," Federer said. "Today I think when I take enough rest, feel hungry and have the fire, then it’s the one I can play my best. I want to make sure I’m happy to be on the court and happy to do press.

"It’s like if I do too much, the fire is like Juuuu ... it goes away. So for me, the family is my priority and then the rest."

Photo credit: Shanghai Rolex Masters