Precor Ab-X machine
 

Does this thing really work?

Sorry, posted this in the wrong section and cannot figure out how to delete it.

For whatever it's worth, I think abs are the easiest parts of your body to exercise without buying machines. Planks, burpees, and actually even pushups all focus on the core.

Compound exercises (those which do not target one specific muscle, but a group of muscles working together) such as squats and deadlifts engage the core too.

Thanks for your help. I have just been using the one at the gym, but I know what you mentioned is surely better.