"The Rock" goes soft for kids

What's Dwayne Johnson's key to maintaining a buff body at the age of 37? "Exfoliation," he says, cracking himself up mightily. "That and drinking cobra blood."

He's just kidding. (We think.) But the infectious enthusiasm the muscular actor showed first on the gridiron, later in a wrestling ring and now onscreen is no laughing matter. His latest film, "Tooth Fairy," is in theaters Jan. 22.

Johnson strapped on ice skates for the first time to play a rough-and-tumble hockey player forced to serve a week as a real-life tooth fairy. He says he likes to channel the same kind of characters that he loved growing up. "For me, that was Harrison Ford in 'Indiana Jones' and 'Star Wars,' and Clint Eastwood in things like 'Every Which Way but Loose,'" Johnson says. "My heroes were the ones who always had fun, ultimately delivered on their promises and kicked a lot of butt along the way."

Johnson has maintained his bulging biceps over the years but confesses that his workouts are a lot different from those during his wrestling and football days. Now, he says he trains smarter and listens to his body more than he did in his 20s.

"It still involves moving a lot of weight, and I love gripping iron," says Johnson, who played football at the University of Miami and in the Canadian league before he became a household name as a cocky pro wrestler known simply as "The Rock."

He also has been flexing his comedic muscles on TV, guesting on "Saturday Night Live" as "The Rock Obama," an incredibly hulked-out spoof of the president. Johnson received the presidential seal of approval: "He's a buddy of mine," Johnson says of Obama, who invited the actor and his family to the White House. "He's still an athlete, so he understands that when you grow up in locker rooms, nobody's safe. We take jabs at everybody. It's all out of love."

His favorite role is doting dad. Several years ago, he bought a farm in Virginia, where he keeps horses for his 8-year-old daughter, Simone. He has a close relationship with ex-wife Dany Garcia; they raise Simone together and continue to be business partners. "There was tripping and falling and being in a lot of sludge over the years," he says of their dynamic, "until we got up, washed ourselves of all that and said, 'Now let's be the best parents we can be in the eyes of our little girl.' "

He hopes to have another child one day and would love to get married again. Johnson does find time to date -- "My love life is lovely," he says -- and looks for a woman who is "smart, has a great sense of self and independence and loves to laugh." And, yes, a taste for cobra blood. "Well, they have no choice about that," Johnson chuckles. "If I like it, they like it."