Exactly. Which is why when I get tired of standing go do something else for awhile (great to remind yourself to take breaks) or I lie down for a bit. For me if the option is there to sit, I end up sitting down and not realizing how long I've been sitting. Standing also guarantees you keep moving around, you can't stand without moving around for very long, unlike sitting where you can easily not move at all.

Yup, I was going to answer standing desk. I had surgery on my l4/l5 and after recovering from all that ended up with a pinched nerve in my neck. Got a standing desk and fixed it all. I stand all day, I don't even have a desk chair. If I get tired of standing I go do something else or lie down for a bit. (WFH is helpful) But sitting all day is a recipe for disaster in my experience.