I am a 20 year old female and substantially over weight. I have been the same weight for the last five years or so. Within the last month I have started to have some back pain. My back is always just slightly uncomfortable but I have noticed that it now has been cracking very often. Almost every time I sit up straight it cracks. It is mostly in the very center of my back It is a bit uncomfortable. Do you think it is cause of the weight? Should I do some yoga or a certain exercise every day? Thanks for any help given