Keeping the stomach in check!

[Redgrave101]

I have always been slim, still am. But i have recently noticed others who used to be as slim as me have started to develop little 'pot bellies' so they still have a slim frame but their stomach tends to kinda 'pop out'.
Anyway i work out using modest weights, a cycling machine, a rowing machine and peform basic sit ups on a fairly regular basis (though i do tend to go through phases of not exercising at all)
So im looking for any tips really on how to best keep a stomach in shape and also toned. im not suggesting arny style, just fit/healthy.
Anyone got any tips/pointers to share??

I realise that it wouldn't hurt to cut out the 'not exercising phases!)

[kenny57028]

I'm also working on my stomach. My upper body strength is getting pretty big, but I'd suggest running to burn calories and watch what fatty foods you eat. Also do crunches, bicycles, and sets of leg raises at 6" , 12" , and 24".