V-Crunch (on BOSU Ball)

Sitting on a BOSU with the hands on the floor behind, lean back with long legs, then fold up: the legs rise toward vertical as the chest comes upright.

How to do it

Setup

Seated on the dome, hands on the floor behind the hips, torso leaning back, legs long and just off the floor.

Steps

Raise the straight legs toward vertical as the torso comes upright.
Balance on the dome at the top for a beat.
Lean back and lower the legs until they hover over the floor.

Common mistakes

Pushing up with the hands: they steady you; the abs fold you. Knees bending on the way up: legs long throughout. Feet dropping to the floor between reps: they hover; the tension stays on.

Breathing

Exhale on the crunch, inhale lowering.