BOSU Crunch

Lying back on the half-ball, curl the torso up and lower with control.

How to do it

Setup

Lower back on the dome, feet flat and wide enough to balance, hands behind the head.

Steps

Curl the ribs toward the hips.
Keep the lower back on the dome – it is a short arc.
Lower slowly until the abs stretch over the ball.

Common mistakes

Sitting all the way up: the abs give the work away; keep it a short crunch. Yanking the neck: chin off the chest. Feet sliding: plant them wider.

Breathing

Exhale up, inhale down.