Moreover, you are not working your core properly with crunches! All this effort and that too for nothing! We then come to the next obvious question – If not crunches, then what? Crunchless Core! This regime consists of powerful and well-planned exercises that aim to ‘reset your core’ These exercises work your core in totality and not in isolation, like the others. This method results in better results in less time.

https://www.youtube.com/watch?v=bj-xvKOl_WQ