Since May, I have stiffness and muscle soreness most of the time especially when I wake up in the morning, very stiff. The soreness is in my legs, back and arm muscles. Even when I sit for short periods of time and stand up my legs are very stiff. Exercise or work wise, I am not doing anything different. I walk two miles every morning and workout three times a week in the gym, and I have been doing this for many years.