Calm down and slim down at YogaPoser.

YogaPoser founder James Brown has shaped up Sting, Ralph Fiennes and Rachel Weisz, so we feel confident entrusting our New Year's fitness resolutions to his studio. Check out The AssKicker--a 60-minute yoga class that flows through cardio and Plyometrics. To warm up the body and begin the challenge, most A-Kicker classes begin with the Navasana pose (pictured, bottom) which targets the abdominal wall. The Astavakrasana pose (pictured, top) challenges the arms, upper body, hamstrings and core. The idea behind this position is to create a foundation that targets all of the muscles needed to get into and hold the arm balance. In other words, if you can hold the position, you're probably toning something.