I'm guessing the reporting on things other than just standing varies widely too. Personal anecdote from a person who spends a lot more of the day standing than

I'm guessing the reporting on things other than just standing varies widely too. Personal anecdote from a person who spends a lot more of the day standing than most people I know: What counts in my brain as simply "returning books to the library" would count as exercise - specifically, "hour of brisk walking" for most people I know. And for many of them it would count as unusually strenuous exercise, whereas for me it's just everyday transportation and doesn't really count as exercise at all. Even if were to be specifically asked to keep track of it, I suspect I'd still end up underreporting it. I was recently surprised to discover my brother lives more than a mile away from me. I make that walk all the time, and had thought it was about half as much. It makes me worry that participant self-reporting cannot seriously be considered a reasonable way to measure levels of physical activity. At least, not without research specifically designed to validate it for that purpose. Which might exist. I really haven't looked into it. If it does, please ignore all previous inane babble.