I don't know how much help I can be, as we ride year-round here in Phoenix. However, I can tell you this, the thing that bothers me most after a lay-off is my lower back. Sometimes I think it is the weight of the Camelbak. The main cure for me is riding regularly. When my back acts up, I also get busy on core body strength with the Swiss ball. The exercises feel good on the back while doing them, and tone muscles that help with preventing the back ache. Good luck!