LOL!!! That's actually a question I've been asking myself for some time now. I use the elliptical quite often. 4 times a week. I haven't lost any substantial weight using it. However, I'm trying to build muscle so I don't usually go over 20 minutes. A couple hundred calories at time. I use it for cardio purposes only. Increase my stamina per se. I would have to say if you use it to lose weight it will probably work. That means using it for 30 or more minutes 5 or more times a week.