Like a lot of people, I sit in a chair much of the day for work. Not always the same chair, sometimes I sit at a bench instead of a desk. In that case, I'm not always staring at a screen, but there's usually one nearby.
I try to get up and walk around. Sometimes to the bathroom or the vending machine, other times to somewhere else in the building, just to walk. I think it's important. Home or at work, moving around is good.
I'm not as active as I'd like, but I try to move. Humans are adaptable creatures, but we weren't meant to stay still all day, every day.