just a small study but food for thought, aerobic/weight training exercise has other non-pd benefits.
https://nwpf.org/stay-informed/news/...0%99s-disease/
this was a retrospective study, patients described their activities. after re-reading this study, i wouldn't have posted it except to say that it confirms exercise doesn't have to be strenuous to help.
one can speculate that those that are busy all day long are also better medicated and take their drugs when they're supposed to so they "work at" being active. lots of variables here.