Lean belly, with Crunch or Sit-ups

Crunch sit-ups and exercises that are often conducted to obtain a slim stomach. However, compared sit-ups, it was crunch exercise your abdominal muscles more effectively.
Target muscles are trained to crunch focuses on your abdominal muscles. As for sit-ups, more muscles other than the abdominal muscles.

For starters, crunch exercise easier to do than sit-ups. [...]