You can't lift stuff while seated?
Nope. I have medical problems that prevent me from training right now. I did so for a while but today there was, for lack of a medical term (I am dumb), a flare up. I went to the hospital and when I was done the doctor said I should not do anything for a few days. Including heavy work. How well I can walk later will decide if I go into work tomorrow. I am fortunate in that they often find "light duty" for me! I am grateful for my job as it provides for my family.
On top of that all one need do is look at Coleman to know it is best to do as your physicians tell you. He's not exactly a walking poster-boy of what to do...