Abs-olute Truths...

Rumor - crunches alone will contour your core.

Reality - This old go-to does strengthen the rectus abdominis.  But, to sculpt your entire middle, you need to do moves that fire up the obliques - the muscles along the sides of your waist and the transverse abdominis - the muscles that run horizontally across your belly, too.  Add planks and twist to add to the mix for a well-rounded plan!