kutujayus

depends what u say bigger or smaller??..
if you are thin, it makes you bigger by bit...
if you are thin you can see a bit of your 6 pack
so it makes it bigger..

if u are over weight... sits up makes no diff.... coz the muscle is being covered by the fat
go for tread mills instead...

sit up doesn't makes the fat around your stomach lesser..
as there are research, if this is true, then people who chew chewing gums oftenly would have very thin cheek and jaw....