Muscle Building: Isolation Exercise - Situps (Knees in the Air)

Lie on the floor with your knees bent and feet crossed in the air. Place your hands at the sides of your head and sit up, forcing your head toward your knees, while keeping your legs and feet as stationary and steady as possible. Really try to crunch your abs at the top of the movement. Lower yourself back to the starting position slowly. (Placing your hands on your lower abdomen will make this exercise easier). This exercise works both upper and lower abs.