The American Council on Exercise did a study to determine the most effective ab exercises.
Here is a list of the 10 most effective exercises, according to the study:
1. Bicycle Exercise
2. Captain's Chair
3. Exercise Ball Crunch
4. Vertical Leg Crunch
5. Torso Track
6. Long Arm Crunch
7. Reverse Crunch
8. Full Vertical Crunch
9. Ab Rocker
10. Plank on Elbows and Toes