With those sculpted limbs, an army of LBDs and gleaming locks, Jennifer Aniston is timeless — and logic defying.

“I don’t feel my age,” she says in the March issue of InStyle. “I feel young every day. It’s in the spirit.”

Crediting cardio, a balanced diet and an arsenal of must-have products for her looks, the Wanderlust star confesses she is a creature of habit. “On the red carpet, it’s time for me to start doing something different,” she says. “I play it very safe because I just want to be comfortable … if I could wear a jersey tank that went down to the floor, I would.”

The natural brunette is also considering ditching the golden hue that has become her trademark. “I’ve been thinking about dyeing my hair a dark brown,” she says. “I feel it would be healthier.”

But while she approaches beauty with a seasoned pragmatism, Aniston says boyfriend Justin Theroux‘s convictions do not affect her own. ”He has great style,” she confesses. “It’s very specific, and it has been his style forever. Has it influenced mine? No, but I know people say it has.” To read more on Aniston’s fashion philosophy, pick up the March issue of InStyle, on stands Feb. 10.