Begin in the plank position with your hands underneath your shoulders and your body in one straight line.
Simultaneously cross your right hand toward the left as you step your left foot out to the left. Then simultaneously step your left hand and right foot to the left, returning to the plank position. Your hands move together as your feet step apart. Take two more steps in this direction, keeping your abs pulled toward your spine and your pelvis level.
Reverse directions, taking three steps to the right. This completes one rep.