It seems that most people do high reps when it comes to abdominal exercise. I myself have dome thousands of crunches and I keep thinking "why is building Abs different then any other muscle?" I wouldn?t do 40 reps of bench unless I was trying a shock routine.
I recently started holding a plate against my chest so that I can only do 10-15 reps. I would much rather do higher weight and lower reps because high reps are tedious and prolong the pain. I would rather get them over with quicker by raising the weight and lowering the reps.
My question is it better to bang out higher reps with just your body weight as resistance?