Exercise to feel younger?

amerr

I mainly used this site to count calories and lost 15 pounds by doing that. I'm only 30, but I'm already starting to feel "old." My knees hurt, my hips feel out of joint most of the time, etc. I'm wondering, if I start to exercise on a regular basis will it help with any of this? It seems like I shouldn't be in so much pain all the time. FYI, I'm not overweight at all, I'm perfectly happy with my weight, which I'm not going to share because I don't want to hear that I should gain weight.