Lie on your back holding an exercise ball above your chest, extending your feet up toward the ceiling.
On an exhale, move your arms and legs away from each other, lowering both toward the ground. Inhale to bring them back toward each other, and transfer the ball from your hands to your legs.
Then lower your arms and legs toward the floor away from each other.
Bring them back together, transferring the ball back to your hands to complete one rep.