This was originally a reply to Jamal's message (13), but I
(also) neglected to select the option to send it to the board:

There is a website, rehabinfo.net, for a group at UC Davis called the
Rehab. Research and Training Center. They have a link to a paper
titled The Role of Exercise in Neuromuscular Disease, in which the
author notes that although research is lacking, strength and aerobic
exercises might be helpful, but require caution. Maybe a lot of hits
on the website would encourage some research!