One Leg Circles is a Classical Pilates exercise. One Leg Circles is performed before Rolling Like a Ball. It is a great hamstring stretch to warm up the hip joint and challenge pelvic stability. Begin by lying on your back with one leg extended up to the ceiling and the other leg stretched out long on the Mat. Circle your leg, using smaller circles for Beginners and larger circles for a challenge. Try not to move hips while circling your leg. This exercise can also be performed on the Tower with one foot under the strap or with a Magic Circle between hands.