So many different thoughts on this topic. Is it true that you can lose weight only doing strength training? Absolutely. You can get that body that you have always wanted by not being afraid to lift heavy. Provided you are working your way up to that and making sure your form is correct. (I would recommend using a trainer for quite some time as well as having a spotter)
But why do we even need to run around like crazy people? Well, the fact is that you need to be taking care of your heart health as well. So in my opinion you really need a good balance of strength training and cardio. That doesn’t mean you have to be running marathons, but you do need to get your heart rate up to keep it functioning well. You would definitely want to consult your doctor before starting and kind of cardio program. There are formulas out there to help you figure out where your heart rate needs to be to burn off some fat or just get to the good cardio zone.
I am not saying that you have to do both…but let me just say that I will always be doing both. 🙂