There has to be a happy medium between some form of activity and over-exertion. And for the time being, I think it is best to stay in that happy medium. This is a non-invasive machine to assist breathing, especially at night. It can be used if there is a profound weakness of the respiratory muscles or if the patient has sleep apnea. A. Tough question which would take pages to explain and my answer is based more on an idea than on very specific knowledge.
Motor neurons appear to be very sensitive to the effects of free radicals.
A free radical is a molecule that can oxidize things in the cell, e.g., lipids, DNA and proteins and make them not function properly. We found that the motor neuron generates a pulse of free radicals when it is about to die. If one can block the action of free radicals then you can prevent or slow down motor neuron cell death. This loss of terminal axons over time after polio, and why these degenerate is not known at present. A possible mechanism for degeneration. involves free radicals that they be oxidizing the lipids and proteins in the nerve terminal.