Straight from our friends at Shape  is this Pilates workout that Molly Sims loves.
Pilates fans include A-listers Madonna , Molly Sims, Christy Turlington, and Claire Danes , all of whom have trained with Alycea Ungaro, author of the new ebook Pilates: Body in Motion  ($10). Ungaro's exercises and tricks can help you tighten your core, lengthen your muscles, and tone your entire body to look camera-ready in a flash. Try this routine she uses to help the gorgeous Sims achieve her incredible red-carpet-worthy physique, and you'll see a slimmer waist, leaner legs, and more sculpted arms in no time.
How it works: Three or four days a week, do each exercise back to back, and be sure to incorporate Ungaro's signature twists to take each move up a notch.
You'll need: Mat
Roll Like a Ball 
Develops control of your abs and increases spinal flexibility
Basic version: Sit on a mat with knees pulled in tight to chest and hands holding ankles. Lift feet off the mat, curve spin, draw in abs, and lower head to form a ball. Roll back to shoulders, then roll back up to starting position. Do 8 to 10 reps.
Ungaro's spin: Work on varying the tempo, rolling back at one speed and coming upright at a much slower tempo to really target the abs and increase strength immediately.
Teaser III 
Works the entire core with special emphasis on the abs and glutes
Basic version: Lie on back with arms and legs outstretched. Scoop in abs as you simultaneously roll upper and lower body off the mat until body forms a V shape (Teaser position) with arms reaching over legs. Raise arms above head and return to starting position, rolling through the spine and lowering legs forward and arms back as abs press low back toward the ground. Do 5 to 6 reps.
Ungaro's spin: This is a tough move to tackle without some gradual prep, so start by working the descent: Begin in a Teaser with arms and legs up to the sky, then carefully reach your arms back and your legs forward as you lower 6 inches. Rise back up and increase the distance you lower: 8 inches, then 10, then 12. These movements call on the glutes to control the movement.
Pilates Pushups 
Targets the arms, upper back, and abs
Basic version: Stand upright and fold forward over legs, reaching hands for the mat. Walk legs out to a plank position and perform 3 triceps pushups, keeping glutes and abs engaged. Pike hips up and walk hands back in to feet before rolling back up to starting position. Do 3 sets of 3 reps.
Ungaro's spin: Be careful not to fall into a yoga-style chaturanga. To keep it clean, keep your hands right under your shoulders to start. Open your elbows wide as you lower, then pull them in tightly towards the body. (This works the medial head of the tricep for an added bonus.) Hover before pressing back up.
Kneeling Side Kicks 
Blast the muscles in your waist, hips, and outer thighs
Basic version: Come to a kneeling side plank with right hand under right shoulder, right knee bent, and left leg long so body is one long line and hips are stacked. Look forward and place left hand behind head. Lift left leg as high as possible and make small circles in the air clockwise, accenting the lift at the highest point each time. Do 10 reps, then switch sides to complete the set.
Ungaro's spin: Draw out the time between each rep and focus on maximum leg length, which will increase the load to the muscles: The longer you stretch the leg, the harder your hip muscles have to work.
Source: Getty / Michael Tran