From PEOPLE Magazine Click to enlarge
SHE'S 51!

Sheryl Crow

"I stay really active," says the rocker mom of sons Wyatt, 6 and Levi, 3. "Having little children is about getting down and rolling around with them. I try to eat fish at least every other day, and I've given up food with red dye in it. But salt is my weakness. I haven't done any Botox. Sometimes people rob their youth by disabling their expressions. Natural beauty is when you're using your natural facial expressions."

SHE'S 42!

Leslie Mann

America's funny-girl-next-door doesn't feel pressure to look red carpet ready 24/7. "I'm not the sexy bombshell," she says. "I'm the normal mom." The Bling Ring star—and mother of two daughters with producer husband Judd Apatow—has found her secret weapon for staying fit. "I'm addicted to SoulCycle," she says of the exercise-bike class. Still, she admits, "I miss my 22-year-old butt!"

SHE'S 75!

Jane Fonda

Legendary actress (and fitness guru) Jane Fonda works hard to maintain a smoking-hot bod that women of all ages would envy. "I do yoga three times a week," she says. "I'm learning tai chi, and when I go home, my assistant drops me at the bottom of the hill and it's a mile to walk up." Plus, "I don't forget to take supplements; I moisturize; I have a lover [music producer Richard Perry, 70]; and I'm careful about what I eat."

SHE'S 40!

Gabrielle Union

It wasn't until her mid-30s that the actress discovered a key beauty secret. "I started drinking a gallon of water a day," says Union. "It changed everything from weight maintenance to hair, skin, nails and digestion." When she's not working, Union hits the gym to do a mix of yoga and cardio. Plus, "I stay young by dating younger," she adds (her beau is NBA star Dwyane Wade, 31). "Dip into the kiddie pool, ladies! It worked for me."

SHE'S 40!

Portia de Rossi

For years she was known for having long hair, but the Arrested Development star chopped it off just before turning 40. "I felt tethered by it," she says. "Part of aging is the opportunity to do something different, and the one thing I don't want to do is chase what I looked like when I was 20." De Rossi credits her youthful look to the vegan diet she and wife Ellen DeGeneres adopted six years ago. "It's changed my skin tone and certainly my body," she says. "I feel healthier, and I don't gain weight!"