(A) Get in high plank position on your hands and toes.(B) Shift your weight to your left hand as you turn your body to the right; bend your right leg behind you and extend your right arm up. Return to the center and repeat on the opposite side. Continue, alternating sides.Make it easier: Don’t raise your arm after you bend your leg behind you.Make it harder: Balance with your arm and leg extended for two counts.

The diagram shows the most used muscles on this exercise