> Only trivially small ones that we'd do a few times a week. There's still lots of physical activity that we do (eg walking around, carrying things like shopping, sex, etc).
Not everywhere — one of the major reasons fitness (and BMI) is correlated with walkability of a city is that in many typical US cities, you barely have to walk anymore, while in the more walkable cities driving is less possible, and you’ll walk or cycle much more, and usually use transit more (which means walking to/from the stops).
It's not so much that as that you CAN'T walk around in most cities. The last place I lived Walmart was several miles down the road which had no sidewalks and was trenches for water 3 inches from the road. No bike lanes, no nothing. It isn't that most of America is difficult to walk through, it is impossible (if you don't want to be hit by a car at least).
It adds up a lot. I split my time between a typical suburban car-centric city (Minneapolis), and a place just off the El in Chicago.
The weeks I am in Chicago I lose weight without really trying - simply from walking to/from the train every day and around the neighborhood running errands. Then of course lunch in the office which of course is another walk away. All those little walking trips add up to miles/day without even noticing and add up to a noticeable change in weight loss/gain.
Minneapolis it's rare to walk more than 100ft (to a car and back) to go anywhere - unless you make a concerted conscious effort to take time to walk for the sake of walking.
Most of the US is low-density and built for cars, so not a lot of walking happening. Also some people in the city will take a Bird or Lyft scooter automating out walking
Not everywhere — one of the major reasons fitness (and BMI) is correlated with walkability of a city is that in many typical US cities, you barely have to walk anymore, while in the more walkable cities driving is less possible, and you’ll walk or cycle much more, and usually use transit more (which means walking to/from the stops).
All this adds up.