Butt and Thigh Workout

The annual Muscle Milk Fitness Retreat always brings out some of the best trainers in Hollywood—and the chance for SHAPE fitness editors to sweat beside stars! During this year's event, we took a Pussycat Dolls dance class with Robin Antin, a Rock Bottom Body session with Teddy Bass (who’s sculpted Cameron Diaz), and punched out our aggression during a BodyBox class with Audrina Patridge’s go-to guy, Jarret del Bene. Want a taste of the celeb workout treatment? Try these three lower-body moves—courtesy of three celebrity trainers at the Muscle Milk Fitness Retreat.

Workout details: Perform one set of the prescribed number of reps for each exercise without resting in-between, and then repeat the entire circuit one more time.

Lower-Body Exercise 1: Side Step

This lower-body blaster comes straight from trainer Andrea Orbeck, whose celeb-client roster includes Heidi Klum, Karolina Kurkova, and Amanda Bynes.
Body parts: butt and thighs
How to do it: Stand with feet together and hands clasped in front of your chest. Push off left foot and hop to the right [shown], landing with weight on right foot. Immediately repeat in opposite direction. Continue, quickly hopping from side to side for 1–2 minutes total.

Lower-Body Exercise 2: Kettlebell Squat

This super-effective exercise is a favorite of Doug Reinheart, who is best known for his appearance on MTV’s The Hills and playing baseball for the minor league affiliates of Los Angeles Angels of Anaheim and Baltimore Orioles.
Body parts: butt and thighs
How to do it: Stand with feet wide, toes pointing forward, and hold a heavy kettlebell (or dumbbell) in front of hips with palms facing toward you. Keeping your chest lifted, squat until your thighs are parallel to the ground [shown]. Pause, and then rise up to standing and repeat. Do 20–25 reps.

Lower-Body Exercise 3: Single-Leg Bridge

Juliet Kaska, who among others has trained Pink, Stacy Kiebler, and Kate Walsh, shared this multi-tasking toning move.
Body parts: butt, thighs, and core
How to do it: Lie faceup with knees bent and feet flat on the ground, arms extended at sides. Raise right leg straight up, foot flexed. Keeping right leg raised, lift hips until body is aligned from left knee to shoulders [shown]. Lower hips until they nearly touch the ground, then repeat. Do 20–25 reps, then switch sides to complete set.