We're not disagreeing that exercise is good. I also happen to be very pro-exercise. What I'm trying to do here is reckon with the fact that, as you say "exercise, athleticism, sports are celebrated everywhere and anywhere you turn", and yet the obesity epidemic only got worse. And providing the same kinds of answers for the loneliness epidemic will show similar results. It's possible that this disagreement is rooted in differing understandings of what "social infrastructure" means.