This is a big topic. One must regain fitness and strength that has been lost without restarting symptoms. Good fitness and strength are also, I believe, a long term insurance against future problems. The stronger you are the more you can do before overloading your muscles, and the fewer everyday activities there are that can cause physical strain.

My physical rehabilitation was quite slow. I have done sports training in the past (used to train for triathlons) but could not train anywhere near the level I was used to, regaining fitness was a far slower process than when I had lost fitness in the past. Also, I believe, by having cut back my activities so much over a period of time I had lost even my fitness for ordinary everyday activities. Even if you do not physical training / gym / sport every day activities provide a considerable level of physical fitness. Driving your car, carrying a bag, peeling veges, putting out washing, doing a few hours writing. Its surprising how much physical fitness just these give you. You don't realise how much until you lose this fitness (as someone bed-ridden, or crippled for a long period must also). It is then that you find everyday activities that once were trivial are now a physical strain and physically stressful. And such physical stress can cause TP reactivation. A difficult situation. I needed to regain everyday fitness before worrying about starting typing or writing.