From PEOPLE Magazine Click to enlarge
Betty Grable
AGE 27 1943

Jennifer Morrison
AGE 29

While posing as popular World War II pinup Betty Grable, House star Jennifer Morrison felt "a little bit of pressure," she says. "Her body is beautiful. There's no way anybody today would not say she's incredibly sexy. I have a lot to live up to." Luckily, her athletic lifestyle works in her favor. "I've always been active physically," says Morrison, a former dancer who recently added boxing to her workout rotation. Just don't ask her to start counting calories. "I'm very lucky. I don't put rigid restrictions on myself," she says. "At one point I'm going to reach an age where my metabolism does not run at the rate that it does and I will not be able to eat a bag of Cool Ranch Doritos whenever I want. So I figure I should enjoy it while I have it!"

Nan Wood Graham
AGE 31 1930

Sarah Chalke
AGE 32

In a re-creation of Grant Wood's American Gothic painting, portraying a stoic farmer's daughter (the artist's sister served as model) didn't daunt Sarah Chalke. "I was psyched to camp it up," says the Scrubs star, whose inspiration was "a naughty bride who was a bit of a gold digger laden with ridiculous jewels the farmer bought her." While the original model looked "severe and serious," Chalke maintains her more youthful glow with daily sunscreen and a new addition to her beauty regimen: eye cream. After her 30th birthday, "I definitely started to notice the wrinkle under my eye when I smile," she says. "I was like, We've got to slow this process down. I've never used an eye cream, but I should get on that train!"

Anne Bancroft
AGE 36 1967

Gabrielle Union
AGE 36

Gabrielle Union admits she was taken aback when asked to transform into The Graduate's infamous seductress, who sleeps with her daughter's boyfriend. "My first reaction was, 'Do you think I'm that old?' " she says with a laugh. "I always thought Mrs. Robinson was more mom age." While Anne Bancroft was styled to look more matronly onscreen, here's to you, Ms. Union, for showing off the sexier side of 36. "I'm going to be brutally honest: There is nothing about working out I enjoy except the results. It's all painful," says Union, who stars in the upcoming film Cadillac Records. A "beanpole" in her 20s, she initially "joined Bally [gym] because that's where the hot guys were." But by 27, "things I ate started to show up in places it never showed up before!" Still, there are some advantages to "developing curves in my thighs and hips," says Union. "I love looking like a woman."

Anna Whistler
AGE 67 1871

Ann-Margret
AGE 67

In Portrait of the Artist's Mother, painter James Abbott McNeill Whistler immortalized his mom as a woman who looks "depressed, lonely, austere and lifeless," says Ann-Margret. "I thought it would be fun to show a 67-year-old in 2008: a healthy, happy, mischievous, confident woman who is certainly not lonely!" Especially when she's working out. Alongside her husband of 41 years, actor Roger Smith, she works out three times a week in their home gym ("We call it the torture chamber"), and once a week "we go hiking with dancers I have worked with and friends," she says. Compared to the stark 19th-century lifestyle of Whistler's mother, today "it's a different world. People are exercising and eating better," says Ann-Margret. "I just want to be the best that I can be at whatever age I am."