The time I spend not being sedentary is also the time I don't spend in front of screens.
I make use of the Pomodoro Technique, and walk in 25 minute cycles, and then sit for a few minutes while I break. After a couple of hours of doing that, I'll sit down for an hour.
This is my office setup: https://www.dropbox.com/s/089qqvaa7j5ob77/office_setup.jpg?d...
* Buy tinted glasses that filter out blue light; darken websites & text editors & terminals
* Have a set of dumbbells nearby that you can exercise with
You can read more infomation about it here: https://lowbluelights.com/the-science-behind-lbl/
Filter blue light, use small screens, use arc dark theme, reduce brightness to match daylight time.
Take micro breaks (walk to your mailbox, get coffee, walk the dog, whatever).
* f.lux
* pomodro sessions and walk-breaks
* compulsively execute post-work 1hr evening exercise
* at least 6 hour sleep everyday in darkish room.
* Live with hope that these counter most of the sedentary work-lifestyle damage :)