Don't know what it is called but it is essentially sit-ups on an incline. It is a board that you can elevate in an angle as you choose. Your feet are on the high-end tucked in under a bar of some sort. Head down. Then you do sit-ups - best stomach workout I ever did Because you are in an incline you shouldn't come up so fast and hence maybe you won't get dizzy doing that.

While you come up you can twist to get the side muscles working as well.