maybe in a village context but everywhere else it's just a way to calm down the herd 

 that's the first use case, second would be bread and circuses, aka 2 minutes of hate 

 Not necessarily. The ancient Greek schools were interested in sporting activities. Although after the children turned 18y, the focus in the gymnasiums was more or less directed for military purposes. I imagine there was little choice once you grow up in a city which is constantly attacked by rival cities. 

 Imagine they even would have opened the windows to get some fresh air. 

 Of course. 

 Yeah.. Life becoming more sedentary and then we have to worry about fitness. 

Even a 2 hour workout and 22 hours sitting / sleeping split is probably not that good. 

 Yes, incedental activity throughout the day would be more normal, but a lot of us have desk jobs. 

 Men also seem to be developing a taste for very thin women. Perhaps trying to start off at a deficit, so that her added-fat doesn't cause her to later be as big as a house.

Women used to just go up a dress size and look a bit plumper. 

 It's been rather strange watching most of the women who were narrower than I become wider.
I always felt so humungous because of my heavy frame.

But I just stayed that way. 

 Our civilization is becoming is more digital and less physical. Whether we like that or not is a different matter. We should at least be open minded to a range of possibilities. And physical excercise is ofc still crucial to live a good life.