I love working abs. It's what I strive for! It's what I diet for! I've also found it to be the most sensitive. One meal or even drinking water will put you in a panic because it just sits right on you're abdominal muscles. So I cut my meal portions; even switched to predominantly veggies; and increased my running distance and speed. What I found was that I had lost weight but abs weren't tight anymore. I had forgotten the simplest, yet most major thing...working my abs!!! Duh! Most exports may say that "abs are not muscles used on a daily basis so there's no need to work them often," however experts are not truly experts...they are also philosophers! We call them experts by the respect they command and not solely by their doctorates. No one knows everything there is to know about our bodies, if so we'd be immortal. The human body is made to withstand any trauma you put on to it and it will eventually adjust. The pain you feel is you're body recovering and adapting. With that said...work those abs as often as you like!!! I have different ab workouts on my "Life After D.E.A.T.H" column as well as a few new ones I haven't posted yet! You can perform mine, 500 [total] crunches a day, or any leg lifting exercises to do the trick.
Cheating D.E.A.T.H is so hard after all huh?!

"A healthy attitude is contagious but don't wait to catch it from others. Be a carrier".
-Tom Stoppard