How do our best-loved celebrities stay so darn sexy year after year? Read on for a few great diet and fitness tips from the stars. Then pick up the new issue of TV Guide magazine — the one with Kelly Ripa on the cover — to get tons more useful info about getting your bod ready for summer!

Jessica Simpson
When she needed to get into butt-kicking shape for The Dukes of Hazzard, Simpson turned to childhood pal Mike Alexander. "Jessica wanted a more muscular butt," says the 26-year-old Texan, who got his friend's assets looking good with 45 minutes of lunges and squats, five to six days a week. "Most women think they have to do tons of cardio, but that doesn't shape muscle," explains Alexander, a trainer at Beverly Hills' Sports Club/LA. "Jessica's goal wasn't to lose weight but to define her legs and glutes."

James Denton
He's married to a fitness trainer (Erin O'Brien), so the Desperate Housewives hottie has no excuse for not looking great. His tips? Eat lots of little meals throughout the day and lay off the beer when you need to drop weight quickly.

Teri HatcherThe Desperate Housewives leading lady stays fit with erotic dance moves learned at the S Factor studio in L.A. "It's great for your muscles and it's really empowering," Hatcher has said, "because it's not about turning a guy on."

Alyssa MilanoThe Charmed sorceress tried cutting out the carbs but found "it wasn't realistic for an Italian who grew up on pasta." Now she stays fit "by doing everything in moderation," including eating cheese, which she calls "the other white meat."

Jennifer AnistonThe Friends star, who was once so curvy that her own father told her she had a rear "you could serve tea off of," dropped 20 lbs. by following the Zone diet. "It's the only thing that works for me," she has said.

Jerry O'ConnellHe once tried to be an Atkins devotee but caved after a couple of days. "I was literally falling asleep on my feet," says the Crossing Jordan star, who says he loves eating carbs (like his favorite meal — a peanut butter sandwich).

Mariska HargitayThe star of Law & Order: Special Victims Unit, who regularly hits the gym, recently took up golf as part of her fitness regime. Good genes — she's the daughter of Jayne Mansfield and former bodybuilder Mickey Hargitay — might have something to do with her fab body, too.

Adam RodriguezHe planned to play pro baseball before injuries sidelined him. Now the CSI: Miami star keeps fit by running on sand.

Debra MessingThe Will & Grace star lost the baby fat she'd gained while pregnant with son Roman not by changing her diet but by hitting the weights and the stationary bike with famed celebrity trainer Gunnar Peterson.

Paula AbdulThe 42-year-old American Idol judge and former Laker girl keeps her shape with private Pilates classes taught by L.A. fitness guru Sebastien Lagree (who also claims Elizabeth Hurley, Jewel, Nicole Kidman and CSI: Miami's Emily Procter among the faithful).

Merrin DungeyShe has dropped 15 lbs. and two dress sizes since joining the cast of Summerland. By cutting sugar and sticking to 4 oz. of protein three times a day, plus lots of fruit and vegetables, "the weight just fell off," says the former Alias star. She also practices pole dancing and even had her own pole installed!

Kelly ClarksonThe original American Idol winner has slimmed down by hitting the treadmill every morning for 90 minutes, but she has said, "If I want a frozen Ding Dong, I'm going to have one!"