I'll echo the sentiments of another poster, in that those making the comments are sedentary and probably overweight, no?
I've never heard adverse comments from people here in Florida; actually, I've had the opposite, in that most people I come across thinks it's great that I'm out there running (or swimming). But, then again, many people here are into fitness. I must see 10 or more runners when I'm out and about training... and cyclists, open water swimmers, people doing yoga, et c. (I train on the beachfront).
I am curious about the demos involved in such remarks.
Stay well,
E.