I think the most important is, well, to do healthy movement and exercise outside of work.

But the second most important while sitting or standing long periods is to change position regularly. Maybe standing desks naturally encourage that by standing around. But some people (and I was guilty too) tend to get a comfy ergo chair, adjust it to their perfect position and then never touch it again. I think we're supposed to regularly readjust. Up and down, tilt and no tilt, arm rests, etc.

Not a doctor tho.