I’ve used a standing desk on-and-off for a few years.
In 2011 I stood for a week before giving up. At the time I claimed that I wasn’t able to focus on my work as well while standing as I was while sitting. Reading that now confuses me as I believe standing is far more conducive to focus than sitting. I think it is because I didn’t push through the initial discomfort of standing. If I had, I’m sure I wouldn’t have had an issue with focus.
In 2014-2015 I tried again and ended up standing for 4 months straight. The first two weeks, I recall, were very hard on my feet and knees. But it was after those initial two weeks that I really began to see the benefits of standing all day (or, at least most of the day). Once those first two weeks of discomfort were over I ended up putting in my longest continuous stretch of using a standing desk. I had to sit down because I injured my ankle playing basketball and could not stand.
I tried standing again earlier this year just prior to moving from a dedicated office to my home office. And I likely would have stuck with it. But once at home I didn’t try standing again until this past week. I hadn’t even thought about it.
This time has been a bit different. I’ve had nearly no discomfort that I’ve had to push through and I’ve noticed an increase of focus almost immediately.
In the past I’ve said that my productivity increases while standing. I’m now not so sure that is the best way to describe it. It isn’t that I get less done when I’m sitting down but I am able to be fully alert and feel no "lull" that I have to push myself through each day. When I have a deadline, I’m going to work like crazy to meet it whether I’m standing or sitting. However, there is a time period each day where I feel less alert or focused or in the mood to work when I’m sitting at a desk. Whereas when I’m standing I feel like I never have that lull in my day.
I still do not own an adjustable desk. I’ve looked at a few but have never made the investment. Sitting all day is definitely bad for your body. Standing all day is also bad. I hope to find the right adjustable desk for me in the near future and give it a whirl.