Flat bench leg pull exercise is very effective for flat stomach. It is a great workout for lower abs and helps to shape your abdomen. Doing this exercise daily promises you a flat stomach. Click the link to access full video on exercises for flat stomach https://www.youtube.com/watch?v=nTVK9s35wIU Watch how to do leg pull here https://www.youtube.com/watch?v=gV0_hxqRY08