Negative Crunches

Sit on the floor with your knees bent and your feet flat on the floor and shoulder-width apart.
 
Extend your arms with your fingers interlaced, palms facing your knees.
 
Begin with your upper body at a slightly less than 90-degree angle to the floor.
 
Lower your body toward the floor, curling your torso forward, rounding your lower back, and keeping your abs contracted.
 
When your body reaches a 45-degree angle to the floor, return to the starting position.
 
You may need to tuck your feet under a set of weights to help maintain balance throughout the exercise.