At age 35, otherwise healthy and having spent 10 years in Herman Miller Aeron chairs, I had hip problems and a small but growing waistline. Then I transitioned to working from home and built my own standing desk (sadly before the very affordable mechanical Ikea standing desk was first released... But which I have now happily used for years). The first few weeks were challenging, but within three months I could stand…
It's due to the standing - my mum spent most of her life standing at the counter in our shop and she has suffered from vein issues since she was about 50. Lots of swelling as well. Like anything, sitting, standing, jumping - it's worth doing everything within reason. Possibly just switching between positions throughout the day. Of course, these things can be gene dependant as well, but if you already have some spider…
I also don't stand like I'm a statue, however. I'm often shifting around a bit, and usually I stand on a nice firm thick padded mat. If nobody is around and I have some good music on, I might even be dancing a bit.