Get Fit Like the Stars

Cameron Diaz

The athletic star keeps her body mini-dress ready by visiting the gym often. Thirty minutes of cardio-alternating between the elliptical trainer, treadmill and bike-helps maintain her mile-long toned legs. The California girl also loves to golf and surf, which certainly contributes to keeping those rock-hard abs and arms tight.

Jessica Biel

The actress works hard to keep her famous tush bikini-ready-even taking to the streets for a workout! She wraps a rubber exercise band around both ankles, then takes 15 lateral steps (out and back) on each side. Biel feels the burn even more by often hitting the track for 40-minute sprint sessions.

Fergie

The Dutchess

keeps her body in rockin' shape with outdoor workouts in Santa Monica, California-often accompanied by her boyfriend, Josh Duhamel. She also burns tons of calories during her hour-and-a-half-long performances. She has said, "I eat low-fat and low-carb and I drink tons of water. I cheat, but I try to make it up by working out."

Reese Witherspoon

This golden girl has always looked great, but lately she's turned it up a notch. Reese loves to run and hike, either alone or with an exercise buddy. One way she keeps her calves toned for summer is by hiking backwards. Another trick: She carries 5-pound weights so she can do strength moves (like squats and bicep curls at the same time) along the way.

Nicole Kidman

Kidman stays long and lean with 55-minute Pilates sessions and walks like these in Brentwood, California, with husband, Keith Urban. She can also be spotted spinning every now and again at L.A.'s Body & Soul fitness studio.

Halle Berry

The sexy actress knows that variety really is the spice of life. Her secret to a great bod relies on changing up the type of workout, number of sets and reps throughout the week. Here, the famously fit Berry gets a workout and shows her support at the Revlon Run/Walk at the same time.

Jessica Alba

Alba stays fit with 30 minutes of cardio, five days a week. As for her abs, the buff actress does crunches while lying on an exercise ball (a Bosu balance trainer, in fact). This works her transverse muscles (one key to a six-pack) because she has to use them to help her balance.

Eva Longoria

The actress stays in shape by power walking in the Hollywood Hills with friends. Other secrets to her hot bod? Her personal trainer, Patrick Murphy, says he never lets her do the same workout twice to keep it interesting. He also advises her to eat a variety of healthy foods and drink lots of water.

Sheryl Crow

Crow says good-bye to flabby underarms by doing tricep extensions to stretch and strengthen her muscles. Stand and hold a dumbbell with both hands, elbows bent behind your head to 90 degrees. Straighten your arms, squeezing the triceps. Repeat until fatigued.

Demi Moore

The 44-year-old keeps her body rock solid by biking, running, and, when she's at her home in Idaho, snow shoeing and cross country skiing. The body is more challenged, as it never gets used to doing only one sport. Changing things up also prevents the wear and tear that comes from repeating a single activity, especially as you get older.

Scarlett Johansson

Johansson is living proof that you don't need to spend all day in the gym to look healthy. During the filming of Match Point, her workouts were straightforward-45 minutes three times a week of simple moves like lunges, push-ups, chin-ups and squats. She did these moves as a circuit-one after the other with no rest in between-to keep her heart rate up, thus combining both strength training and cardio.

Heidi Klum

Since giving birth to her son Johan, the supermodel is taking a more laid-back approach to getting in shape. Instead of vigorous workouts like she did after having son Henry, Klum's now doing yoga several times a week. Two other ways busy new moms can incorporate exercise into their day (and bond with baby): Bounce on a stability ball while holding your infant, or snuggle them in a sling and walk up and down stairs.

Jennifer Hudson

Three basic moves-squats, push-ups, and sit-ups-work every muscle in your body. Hudson does a circuit of 25 each, repeating four times (with a minute of rest in between).