I have this machine I use for abs, and I get good results with it.. When you sit on it, it's kinda like you're sitting on a bike.. Your feet are on 2 pedals, and your arms are grabbing a handlebar type thing.. And you use it by pushing the pedals and pulling the handlebar.. I think it's geared towards like an aerobic type workout.. But what I noticed tho when I 1st started using it, was you could really concentrate on a certain muscle group for isolation.. For example you could focus on your arms or legs primarily, and they'll do most of the work.. I found out also that you could also focus just on your abs.. And the way I use it, I feel I get a nice workout.. At the beginning of the movement you really feel it in the upper abs, and as I push/pull, I arch my lower back and it brings the lower abs and obliques into it.. I've been lucky and always had a six-pack, so I've never done other exercises with weights and stuff, but this seems to get the job done..