Thanks for the response, Andy. He does walk a little but the heat drains him very quickly at the moment and he needs something to supplement the short walks he can take that he can do at home. I was looking at exercises for osteoporosis patients on youtube that I thought might help that are low impact but are designed to increase bone density and I am guessing, muscle. Are there any guidelines you can point me to that indicate safe heart rates during exercise for Thals please? Any exercises that keep him within safe ranges and don't wear him out should be ok, right?