From what I've heard, the best way to avoid loose skin is not to build lots of muscle and that the muscle can plump up some of the skin but that really, there's not much that can be done.....that there will just be loose skin. It used to real bother me because I do have an apron thing of loose skin on my stomach that I got after my second pregnancy with a 9lb. baby but now, I just accept it. I also accept that my arms are a bit flabbier than I'd like. Someone here once said it's better to be thin with loose skin than having fat to fill it up. Doing weights is really great. You can also do other resistance exercises like squats, lunges, push ups, planks, and crunches. Even if it doesn't help with the skin, it will definitely boost your metabolism and calorie burn while at rest. Congrats on all of your weight loss! You have so much to be proud of!