Jennifer Aniston's yoga pro Mandy Ingber (her new DVD, Yogalosophy, is in stores) shares her plan
Step 3: One-Arm Balance (Abs, Legs)
Start in plank position. Walk left palm underneath forehead. Shift weight onto left side of left foot, flexing feet as you stack right foot on top of left foot. Push right hand off floor, shifting weight onto left hand and left leg, and extend right arm to ceiling. Hold 15 seconds. Switch sides.
Credit: Michael Larson