Step 1 : Start in a straight arm plank position with your shoulders stacked above your hands and your feet hip-width apart.
Step 2 : Extend your right arm forward, then place it back down into the plank.
Step 3 : Extend your right arm to the side, then place it back down into the plank.
Step 4 : Keep your body in a straight line as you reach your opposite (left) arm under your body, pull your right leg toward your core, and tap your right foot with your left hand.
Step 5 : Return to the plank position and then repeat on your opposite side.