What's wrong with the "crunch"?

Well, I would be lying if I told you I never did a traditional style sit-up or crunch.  These exercises do, indeed, make you sore in your various abdominal musculature.  However, one of my favorite quotes (and I cannot give credit because I forget the author) is: If our abs were meant to flex our trunk forward, then God (if you believe in the higher power---I live in Athens, GA and Darwin's fish bumper sticker is on every other car) would have placed something that looked like hamstrings across our stomachs.  This is my attempt at some exercise humor, and it leads me into some advice on how to train your abs without flexing your spine.

If you do not believe me when I talk about core training/stability, then listen to Gray Cook, PT, CSCS when he talks about "ab strength vs. core stability".  It is a bit lengthy at 9 minutes, but one can learn a lot no matter what your sport or fitness goals.

The second video (advanced) is an excellent exercise for core stability along with the third video.  The final video is "one to grow on".  I am attempting to master these currently.  You always need to be looking for new challenges.  Enjoy.