umm I'm not trying to be a wet blanket here but just to relate
my own personal experience.
I've been going for 4km run every weekday for the past 18mths and
do 200 situps per day for the past year. I think so far I estimate
I've clocked up about 50,000 to 55,000 of them. Initially I removed
3 inches from my waist but my lower abodmen (just above my groin
area) is more or less the same though it did flatten a bit.
After that, though I continued the same regime, it simply stops
removing more flab and I don't eat breakfast.