good questions to pose about abs

The NY Times published a thorough look at how sit-ups and crunches affect the spine:

http://well.blogs.nytimes.com/2009/06/17/core-myths/

There are lots of points to consider here, but I'm not sure that sit-ups are to be discarded. Once again, Wiserhealth defers to listening to one's own body and doing what feels the most natural.

Bottom line: It is important to have a healthy lower back. So stand straight (like there's an invisible rope pulling your spine upright).