OnlyOnAOL: The secret to Andy Roddick's buff bod (hint: not tennis)

By: Donna Freydkin

When Andy Roddick's actress wife Brooklyn Decker books a vacation, she bypasses swanky private islands and deluxe yachts.

"When she has to take a girls' trip it's always to a national park as opposed to something fancy," says Roddick, who is based in Austin with his family. (See an interview with the cast of "Everybody Wants Some!!," directed by fellow Texan Richard Linklater, above).

It's why Roddick kicked off the centennial celebration for the National Park Service in Austin on Tuesday. Believe it or not, The National Park Service turns 100 on August 25 of this year.

And when it comes to being outside, Roddick loves it. The subject hits close to his heart. As part of his Andy Roddick Foundation, the athlete works to get kids outdoors to learn and play and have fun.

"You have to be passionate about it or you sound like a bit of a salesman. It has to fit. It's a stroke of luck that they were doing this great event in Austin, not far from where we live. The cause is something we believe in," he says. "First and foremost, Brooklyn and I are such fans. We spend a lot of time in parks in North Carolina."

His favorite getaway: Blue Ridge Parkway. "It's where we used to spend our summers. It's pretty cool," says Roddick.

The former top tennis player also hits the great outdoors to stay in shape. We all know how boring the treadmill can get. Roddick can relate. "Given the option, I was a big fan of trail runs and hiking and anything to get out of the monotony of the training session," he says.

Speaking of boring, we have to take a moment to mention Decker's Instagram, which is a joyous amalgam of snark, real-estate porn and odes to her son, Hank. Above all, it's hilarious and honest.

"I like her too. She's great. I feel like most Instagrams are people wanting to present a mirage of themselves and she's the opposite," says Roddick.