Follow these rules if you want to get your chocolate bar.
1. It is very important to work all areas, not limited to the rectus femoris.
2. Must vary as far as possible the exercises, but you've always found that going well.
3. Never leave the room without finishing the series of crunches.
4. Varies with dynamic isometrics.
5. Find a machine plate is almost the only way to vary the resistance.
6. Work to failure.
7. Train in different areas on different days.
8. Controls declines, simply do not go down by gravity.
9. Once you have a good tone abdominal, lumbar introduces an exercise for every four of abs.
10. Always stretch well to end the session.
Source: Men's Health in Spanish