Step by step instructions
Begin in an elbow plank position with feet together and hands clasped, abs braced into spine. Shift weight forward onto toes and lower chest towards the floor (avoid letting hips sag).
Push away from the floor and shift weight back into plank position as left leg extends up and back behind hip (keep hips square to the floor as leg lifts, avoid letting hips sag). Lower left leg to return to start. Repeat on opposite side.