How long can you "build muscle"?

Amanda,  How often are you adding cardio to your routine? I found that in order to loose weight I needed to do cardio of some form 6-7 days a week.   When I have hit plateaus I would reevaluate my routines both weghtlifting and cardio. Increasing resistance and intensity of my routines (on days that I lift weights I do cardio routine afterwards). Also, make sure that you are getting enough protein and stick to complex carbs.  Another, biggie for me was purchasing a Polar heart monitor/strap to make sure that I was working out within my target zones.