Jennie Garth toned up for her comeback role on the new 90210 by working out five days a week with husband actor Peter Facinelli to trainer Tony Horton’s P90X DVDs. “Every day is different,” she says. “One day is really hard yoga. Then arms and shoulders, legs, then karate. His program is made to confuse the muscles so you don’t plateau. I feel better now than I ever have.”

Brooke Shields wore the same pair of jeans she modeled in Calvin Klein ads 28 years ago at a recent bash for the designer’s 40th anniversary. So, how does she stay so fit? “If I stay away from too much carbohydrates, I’m usually better off,” says the 43-year-old mom of two, who also does spinning and yoga. Though whole grains and brown rice are on her menu, Shields doesn’t “believe in denying myself. I don’t want to go through life not enjoying.”

She plays an intense publicist on HBO’s Entourage, but when it comes to her diet, Debi Mazar is much more relaxed. “I believe in balance, nothing too radical,” says Mazar, who hosts UnderTheTuscanGun.com, an online cooking show with husband Gabriele Corcos that focuses on fresh, healthy Tuscan recipes. “I love food, and I love culture. Food is a celebration, so I think when you eat well-balanced, that’s the key.”

Source: People.com (Health section)

According to ‘Shape Magazine’, Grammy-winning vegetarian Carrie Underwood has dropped between 15 and 20 pounds since her American Idol days. How did she do that? By hitting the treadmill, swimming and sticking to healthy foods. Although she admits to a weakness for cheese, Carrie prevents herself from overindulging by keeping a food diary and carrying around whole grain Kashi bars wherever she goes. Nice trick gurl!

As for Kelly Clarkson, the original queen of AI, she does not reportedly believe in diets. However, being in the music business forced her to refined her eating habits (focusing on portion control) and amping up her fitness routine instead of following any particular diet plan. Kelly has told ‘Us Weekly’ that she indulges in her penchant for chocolate, but only to a certain point.

After a five-year battle with bulimia, AI season 5 runner-up Katherine McPhee managed to drop 30 pounds the healthy way by sticking to the Intuitive eating plan. She told Shape Magazine that the plan worked because she can munch on anything she pleases, but when she’s full, she stops. Exercise-wise, Katherine tones her muscles with weight training and likes to walk on the treadmill for 45 minutes four to five days a week.

Can I say WOW?!! Marathons are already hard, but a triathlon? So much harder! But that didn’t stop Jennifer Lopez the diva from joining and getting down & dirty for charity! According to reports, J.Lo finished the Nautica Malibu Triathlon in three and a half hours early today. The singer smiled as she crossed the finish line after swimming, biking and running. Jennifer Lopez also told the onlookers, “Thank you guys so much. This is an amazing day!” What do you think of her fit triathlete body guys? Sexy or not??

Cameron Diaz is not one of those stars who skip breakfast (especially the next day after exercising).

After a hard workout at the Gym on Nemo in West Hollywood, the athletic actress was spotted ordering a big burrito and a full fat latte for breakfast the following day. This only proves that she knows how to balance things in life!

Photo credit: Anthony Dixon / WENN

Britney Spears unintentionally caused some trouble at Bally’s Total Fitness in Culver City last week, when the club accidentally double-booked the same exercise room for both her and another regular scheduled fitness class.

An eyewitness tells OK! that the singer’s trainer booked a room for her at 7 p.m. PT, not realizing that another class was already scheduled to start in the same room at 7:30.

When Bally members showed up for the class, they were told it had been cancelled because Britney was using the room for her private session. This started a frenzy at the otherwise low-key fitness club. Eyewitnesses tell OK! many members thought Britney was behind the mixup and had used her celebrity status to keep the room for herself. [Source]

The fitness club says Britney had nothing to do with the scheduling mixup - they admit it was their fault in double-booking the exercise room.

Sources at the gym also say that Britney has recently been incorporated more vigorous dance training into her workouts - does that mean she’s preparing a big comeback?

Photo credit: WENN

When you are looking for designer handbags or exotic lingerie, the internet is a great place for information and shopping.

Halle Berry got back into shape just two months after giving birth to her first child. Apparently, her secret to losing her pregnancy pounds is just eating healthy and exercising (and probably being in love too, as she just got engaged to her boyfriend and baby-daddy Gabriel Aubry).

In terms of diet, Berry is eating lots of vegetables, lean proteins and complex carbohydrates, as well as drinking a large quantity of water.

The 41-year-old actress also works out for 60 minutes, five days a week with celebrity trainer Ramona Braganza.

Their sessions include three cardio segments – on the elliptical, as well as kickboxing and then a stairs or hill climb – then also does a strength-training routine that include abdominal work and leg exercises. [Source]

Here are some pictures of Halle at the 15th Annual EIF Revlon Run/Walk for Women in Los Angeles last week.

Photo credit: Jody Cortes / WENN