A

SETUP Sitting on a stability ball, hold a 5- to 10-pound dumbbell in each hand and walk feet forward until head, shoulders and upper back are supported on ball, feet hip-width apart. Tighten your abs and butt, and lift hips so body forms a straight line from shoulders to knees. Extend both arms above chest, palms facing forward.

B

ACTION Bend elbows down and out to align with shoulders [B]. Straighten arms to starting position and repeat. Strengthens chest, front shoulders and triceps; abdominals, spine extensors and buttocks work as stabilizers.