Movement: Start lying on a mat on your side with your knees on a comfortable pad. Firmly planting your hand, raise your torso until the arm is straight. With weight on knees and hand, straighten the body so a line forms between your knees, hips and shoulders. Brace through your core at all times. Repeat on opposite side.
Repetitions: Hold for the full prescribed time on one side, then switch sides and repeat. This counts as one set.