Double-Leg Abdominal Press

Step 1. Lie on your back with knees and hips bent at 90 degrees (tabletop).

Step 2. Place your hands on your thighs just above your knees. Push your hands against your knees as hard as possible while using your abs to pull your knees toward your hands.

Step 3. Hold for 10 seconds of maximum effort. Your abs should be shaking.