Thanks for all the replies,
...........but I think they keep seeing all my Strava posts on FB about my workouts, rides, runs and swimming...........
Ahh! the dreaded FB.
I have had similar experience.
First of all, we (myself and Mrs BoldonLad) are a bit older that you (at 70), but, earlier this year, Mrs BoldonLad suffered a slight stroke.
We were both reasonable active, walking, cycling, certainly when compared to friends and relatives.
After discharge from hospital, and, with Doctors approval, Mrs BoldonLad set about regaining her fitness and well being, with my support.
We, use Runkeeper and a Garmin to track our cycling outing and walks. Because some of our relatives live out of the area, indeed, out of the country, I posted the activities to FB. This was intended to reassure absent family members that recovery was going well (which it was, and still is).
Several family members complained that we were "doing too much" (our target was 60 miles per week of walking/cycling, we were typically achieving 70-80 miles per week).
The activity level had Doctor's approval, indeed Doctor was positively enthusiastic at my wife's positive attitude, we resolved to ignore the "doom mongers". IMHO, it is THEY who have a health problem, not us.
The solution may be, as we did, to stop putting every activity on FB !