Intermediate Clams Exercise Once you have build some flexibility, you are ready for the Clams exercise. Lay down on your side, and bend your knees, resting one on top of the other. Then, while you keep your feet together, lift the upper knee away from the other knee, holding them apart for a count of 10 seconds. Slowly lower your knee back down. While performing this exercise, make sure that you do not roll your hips back.