(Cardio burst: 2 minutes)Sit on ball, walk feet forward, and roll torso down until bottom of butt is just off ball and middle and lower back are on ball, feet together. Place hands behind head. Lean back, pressing upper back into ball, then exhale, contract abs, and curl forward until upper back lifts off ball.
A. Make it easier Place feet wider than hip-width apart for more stability, and cross arms over chest.
B. Make it harder Straighten one leg so it’s parallel to floor and you’re balancing on one foot. Do half the repetitions, then switch legs to finish.
( Photograph by Jonathan Pozniak )
(Cardio burst: 2 minutes)Lie over ball on all fours. Walk hands forward so ball rolls under thighs, legs together, abs tight, and body in line from head to toes. Bend knees and pull them and ball (it will roll to shins) toward right shoulder. Hold for 1 second, then roll back out and repeat to left side.
A. Make it easier Hold start position—body in line from head to toes, abs contracted—for 15 to 30 seconds. Repeat one more time.
B. Make it harder Start with ball under shins and let it roll to tops of feet as you draw knees in.