Come into a high plank or an elbow plank. Pull your belly button up and in, and contract your abs and glutes.
Let your heels drop to the right. Rotate your hips so your left hip is stacked over the right.
Reach your left arm to the ceiling. Hold for a few seconds.
Lower your hip to return to a plank and hold for another few seconds.
Repeat on the other side, dropping your heels to the left and stacking your right hip on top of your left. Extend your right arm to the ceiling and hold for a few seconds.