After the birth of my DD#2 my physio told me whilst watching tele, peeling the spuds, feeding bubs etc if you suck your abdomen in and hold it for 5 secs, then release, repeat, then release etc etc you are actually working at strengthening your tum tum muscles. I only did it for a few mins a day (i was a bridesmaid 6 months after my DD#2 birth, so wanted a flat tum tum too)....i actually found it did strengthen my muscles .....i was b/f too though and had normal vag. delivery..