the people with problems exercizing i think are mostly the sensory motor axonal large fiber PN cases. Small fiber can be excruciatingly painful but the motor nerves arent usually involved. Motor nerves have a myelin sheath and are large fiber. Degredation of the axons of motor nerves lead to loss of strength and stamina. I knew i have sensory motor axonal PN but didnt realize how much my motor nerves have become affected until a few days ago when i tried to show my daughter a way of showing a collie involving a smooth gait but i could not lift my legs and for the life of me coulndt run more than a few steps very unsteadily. I noticed nine years ago that my legs got as heavy as tree trunks if i tried to run more than a half block but i could force myself to lift them but not so anymore.