It has been 7 months since my surgery (L5,S1 Fusion) and my experience has been no matter how good you are feeling and how normal your back is feeling....don't over do it! I am still following the blt rule and walking every day, but there are still days that I wake up sore...not just the part of my back where I had surgery, but sometimes my upper back as well. It's usually if I know that I worked too long....like sitting at my desk at work for 11 hours in one day like I did yesterday. This morning, my back feels stiff and I just ache almost all over and all I did different was worked 3 hours more than usual.
Otherwise, I am having so many good days and yesterday on my walk I felt like jogging....but knew better.