Seated knee ups

Sit on a bench or on the floor. Keep your spine straight. Your knees should be bent a little more than 90 degrees. Use you lower abs to raise your knees toward your chest, keeping your knees bent at the same angle. The motion hinges in the hips. Focus on using your lower abs to raise your knees. Use your leg and hip muscles as little as possible. At the top of the motion (knees up), hold the ab muscle contraction for a count of two, then lower back to starting position with the heels lightly touching the ground. Keep constant tension on the ab muscles. Don’t allow the weight to rest on the floor between repetitions, just touch lightly.