Curves, in my experience, won't get you there. It's a good starting point for people who were not active at all before... but it can only take you so far.
Agree with the poster above about the heavy lifting! I got awesome results lifting heavy weights... I haven't been able to, as much as I'd like, in the last year due to child care issues... I'm feeling it in major ways. I've been stuck ever since
. Cardio just doesn't cut it for me! If you build muscle, your body burns more 24/7!