Hello. I am trying to lose some weight and while I can do regular sit ups at home, I can't at work...

To be clear, Sometimes at work I get moved from a cash register to the people greeter post at Wal-Mart. I only work overnights, so when it starts getting slow I can start doing other things at the front. I clean up and move carts forward, but that only lasts so long.

I wear ankle weights usually (5 lbs each) and for the past couple nights I've removed them and lifted them like dumbbells (curls)... Today I noticed some results from the lifting, but I want to work on other areas as well.

So I would like to know if there is a good alternative to sit-ups that I can perform while standing, and without any equipment... Even something that works more or less than sit-ups but gives similar results...

I suppose I could use my ankle weights as equipment if weight is required, but I can't use a resistance band or anything...

Thanks for any advice, even if my request is absurd and unrealistic, thanks for any insight. :)