The Just Go With It star, who turns 42 on Friday, plans to play outside – and work out
Credit: Retna

Would Jennifer Aniston say her new movie Just Go With It, costarring Adam Sandler, reflects her attitude on life right now?

“Absolutely. I would think that it’s sort of so innocuous, it’s a positive thing,” she tells PEOPLE. “It’s truly just about having pure fun.”

To celebrate turning 42 on Friday, Aniston is planning to go away with a group of friends. On the agenda: “Get up, have breakfast, have a workout, do something great outside,” she says. Exercise on vacation? “Yeah, I know, it’s annoying,” she says, laughing. “But that way you feel great.”

Also appearing in the new movie with swimsuit model Brooklyn Decker, Aniston held her own when it came to baring all for sexy bikini scenes.

“If you’re consistently working out, your metabolic rate is constantly at a level where it’s kind of burning,” says Aniston, who maintains her svelte figure with yoga, Pilates and cardio at least four days a week.

But this week’s PEOPLE cover girl still admires Decker’s assets. “She’s so sweet, that girl. She’s just darling and like the nicest person,” Aniston says. “And oh my God, you should see her and [husband] Andy Roddick walk into a room. It’s like, really?”

For more of Aniston’s revealing interview – including her feelings about her famous exes and her pal Courteney Cox – pick up this week’s issue PEOPLE, on newsstands Friday