X-Cross Sit-up

Done in (slow) cadence. Starting position: Lie on your back with legs and arms extended out in an "X" position. On count 1, simultaneously lift your left leg and right arm to meet above your core, keeping both as straight as possible as you touch your right arm to your left leg. Return to the starting "X" position. On count 2, flap-jack with your right leg and left arm, again trying to keep both as straight as possible as you touch your left arm to your right leg above your core. Return to the starting "X" position. On count 3, execute a knee-up by lifting your shoulders and legs off the ground and touching your toes as you bring your knees up, with only your six touching the ground. On count 4, extend your arms and legs and return to the starting "X" position. That is one rep.