Will Smith`s mantra- physical fitness........

Will Smith believes that the key to happiness is being physically fit.

The ``Men in Black`` actor, who had to get in great shape for a number of film roles, thinks that a healthy body is equal to a healthy mind, reports China Daily.

"I feel like everything in my life depends on physical conditioning,” Smith said.

I love eating sweets and everything, but I think the quality of my parenting, the quality of my relationship with my wife - it is all based on being on great physical condition.

"I believe it`s the beginning of finding true happiness,”