The long arm crunch

The long arm crunch is ranked the 6th most effective ab exercise, changing the traditional floor crunch by straightening the arms behind you. This adds a longer lever to the move, adding a bit more challenge and difficulty. This move also emphasizes the upper part of the abs, although it's important to remember that your rectus abdominis is actually one long muscle that travels from your lower chest to your pelvis. While you can emphasize one part, any exercise you do will work the entire muscle.

How to:

1. Lie on a mat and extend the arms straight out behind the head with hands clasped, keeping the arms next to the ears.
2. Contract the abs and lift the shoulder blades off the floor.
3. Keep the arms straight and avoid straining the neck. If you feel neck pain, take one hand behind the head while keeping the other arm extended.
4. Lower and repeat for 1-3 sets of 12-16 reps.
5. You can add intensity by holding a light dumbbell if you need more of a challenge.

View this exercise in the Best Ab Workout.