Los Angeles: Pop Physique
What to expect: A class that earns you a perky ballerina butt that "pops," ? la the perky posterior that greets you on the studio's home page. The mix of pilates, dance and barre moves is set in a "yupster" studio (yuppies and hipsters united) that rocks the latest indie and electro music.
Know before you go: Learn to love that muscle-burning sensation. The program at Pop requires that you hold...hold...and hold a move (like a deep pli?) to get results.
Your turn: Look for the DVDs—three workouts, with one on defining a damn-fine derriere—on the site, starting this month ($15 each).
Los Angeles: Athletic Conditioning
What to expect: Knocking out kettlebell swings, walking lunges and "suicides" (sprinting back and forth on a basketball court). And never again using modifications when it comes to body-weight moves. With this routine, you will be the girl who can blaze through pull-ups and push-ups.
Know before you go: Class goers are super tight and meet regularly to celebrate birthdays and progress.
Your turn: Challenge yourself with the class's 10 percent goal: When you use free weights, grab dumbbells that are at least 10 percent of your body weight. (So if you're 120 pounds, reach for 12-pounds.)
Los Angeles: Full-Blast Yoga
What to expect: Chaturanga to bassthumping Eminem and Katy Perry in a gorgeous studio of floor-to-ceiling windows overlooking Santa Monica Boulevard. The name of this Vinyasa flow represents what volume the music will be turned to, the effort you're expected to give and how you should live every day.
Know before you go: Owner Meaghan Kennedy Townsend shouts words of encouragement during class and gives mini-massages to students while they're in Child's pose.
Your turn: Create a yogi playlist of fast-paced, bumpin' songs—Townsend suggests Tupac's "Changes" and Katy Perry's "Firework"—to fuel your desire to move powerfully through poses.
Los Angeles: BUTI
What to expect: One ridiculously amazing booty. A blend of yoga, strength training and tribal dance equals muscle-sculpting, butt-shaking Buti. The class is a one-stop cardio-sculpt shop: For 75 minutes, you flow from Warrior variations, squats and hip-openers to dancing to bass-heavy jams.
Know before you go: Pull from your "hot yoga" wardrobe. The dress de rigueur is typically skimpy short-shorts and sports bras.
Your turn: Sign up at the site to stream three classes a week for $40 for the first three months.
"At Kinetic Cycling in Cali, KineticCyling.com, a big screen shows motivational footage like the World Cup. It transports you!"—Meaghan B. Murphy, deputy editor.
More: 10 Quick Cardio Moves