Sarah Michelle Gellar's secrets to a healthy life

On a soundstage in Los Angeles, Sarah Michelle Gellar, 34, has just finished filming a scene for her new CW show, Ringer. We sit on a couch on set, a well-thumbed script beside her. Still in an olive gown and full makeup, she's ready for her next scene-oh, except for the pair of white Nikes on her feet. It's a perfect illustration of how this working mom (of 2-year-old Charlotte) and wife (of nine years, to Freddie Prinze Jr.) manages both sides of her life.

Much like the twins she plays on TV, she has twin personas: "I'm Sarah Michelle Gellar when I'm at work," she says, "and I'm Sarah Prinze when I'm not." As the crew sets up the next shot, Sarah talks about her healthy food obsession, why she naps during lunch, and the "weekends off" rule she credits for keeping her happy.

Health.com: 5 ways to a happy, stress-free family

Q: How do you think growing up in New York City affected who you are today?
A: I think, automatically, you look at the world differently if you're from a big city. You're never bored, you don't stay home, you're always on your feet. I think it generates type A personalities.

Q: What are your favorite workouts?
A: I like anything outdoors. But I'm just as happy on a treadmill. I love Pilates. I grew up with, and I still have, major scoliosis. Growing up in Manhattan, you had your schoolbag, but we were so trend-conscious, nobody wanted to put a backpack on both shoulders, so almost all the girls I grew up with have it to some degree, because we all were so lopsided. So Pilates not only is a great exercise, but does relieve a lot of discomfort.

Health.com: Kristin McGee's magic yoga moves

Q: How did you keep fit when you were pregnant?
A: Well, I went into labor at the Pilates gym.

Q: You didn't!
A: And it was funny, too, because I was getting cranky, and I said to my trainer, "I'm just cranky today." She was like, "Maybe it's because you're going to give birth!" And I was like, "Nah, not yet." It turned out I was in labor, I didn't realize.

Q: Have you changed your workout since you started Ringer?
A: Ha, ha, um, if you count walking from Stage 3 to Stage 16! No. If anything, it's downgraded. And I made sure that my body was strong before we started, because these hours are really difficult.

Health.com: What pregnancy does to your health

Q: Do you have a go-to way to lose five pounds?
A: I don't believe in trying to trick your body into things. I eat healthy, I exercise, I love food-but I don't like junk food. I mean, we're women. We go up by five pounds, we lose it, depending on the water, the moon, your cycle, whatever. So I just try to maintain.

Q: You seem so confident. Do you ever have moments of insecurity?
A: Oh God … I'm a female! I totally have body dysmorphic disorder. I think most women do. A makeup artist friend once said, "I don't think I've ever seen you look in a mirror." I'm surrounded by them all the time-you sit in hair and makeup-so I guess I just have this mechanism where I tune it out. So every once in a while, I'll look and I'll be like, "Wait, that's what I look like?" I just have to remember that I'm human, and I'm a mom. Being a parent changes the vanity at least a little bit. It has to. Your priorities are different.

Q: If you were ever to put a famous woman's body on your fridge for inspiration, whose would it be?
A: I would never do that to myself, especially because I'm aware of the airbrushing and trainers and food programs. You have to use yourself as inspiration. I think if I were ever going to put something up, I would put a picture of myself where I was proud of my body. But I would rather not look at a picture of myself on my fridge. In fact, we have a nonmagnetic fridge.

Keep Reading: Health.com: Sarah Michelle Gellar's secrets to a healthy life