My buddy David found out I was working abs and sent me the advice below. It confirms what Nathan has been teaching me.
Biggest mistake people make when trying to develop great abs
Some point along the way we got the idea that if we do a hundred reps for are abs they'll get ripped. Wrong. Abs are like any other muscle. Would you develop your biceps or chest with 100 reps? No.
To develop great abs you need to do two things: develop the muscle and reduce body fat. You can reduce your body fat % by eating right and doing cardio. To develop solid abdominal muscles you need to train your abs the way you train the rest of your muscles. Do the proper rep range, 6-20 reps with is the best rep range for building muscle. Give your muscle the proper amount of rest between workouts, this amount will depend on intensity. And train hard!
He is still selling his 7 disc DVD set , You can buy it here for $29.99. By the way, he is giving me $12 for everyone he sells through the link. Just thought I would share that part.
So stop doing endless sit-ups and crunches if that is your training and follow his advice.