Though historians still disagree on whether Spanish explorer Juan Ponce de León really was in search of the Fountain of Youth, we do know that it remains the trophy at the end of every Hollywood beauty’s red carpet-covered tunnel. But has anyone unveiled the secret to defying the effects of aging? By the looks of her blemish-free skin and always-svelte physique, Jennifer Aniston must have some insight.

To maintain her figure, the former Friends rom-com favorite has her routine down to a science. “I rotate around a lot. I’ve been doing like a spin-yoga combination lately. I also love just a good run, [it’s] really awesome when my knee isn’t screwed up,” she told InStyle Tuesday night in L.A., where the actress and smartwater campaign star was honored for her philanthropic work with St. Jude Children’s Research Hospital. “But yoga’s really, really one of my favorites. It’s so mind, body, soul connection. And that’s always nice to incorporate into your physical activity.”

For smooth, baby-like skin, Aniston turns to Aveeno products, especially their sunscreen. “It smells really good and it’s imperative to wear sun screen. A big ol’ lesson that lots of us from the ‘80s were to learn,” she revealed. To boot, she also stays hydrated with Smartwater and represents the brand because it feels “right and organic.” Potions aside, how—exactly—can we all be just as radiant as the star? For her, the ingredients are simple: “A lot of water. A lot of lotion. And a lot of laughter.”

Speaking of laughter, Aniston believes joy directly prevents the aging process. “I think darkness, depression, not sort of conquering the inside and figuring out what your knots are and untying them is kind of debilitating in a way. And I think being joyful and grateful is always a positive thing,” she quipped. “I mean, imagine, you know how you feel when somebody’s not nice, or you see somebody angry in their car or mad at the checkout stand or whatever, and you just feel so crappy after you’re around that. Or just going on the Internet for a minute. Don’t even do that. I don’t know why they created that, for nasty people with nothing to do, but whatever.”