Stretching! Thank you for making me not seem unreasonable as having this as a goal too. IDK if it'd help you but the sitting for ages at work thing was bothering me too so I got myself a sand timer. They can go up to an hour so it's not like you're setting unreasonable goals. Every time it runs out I get up and move around/stretch, even if I've moved from the desk for genuine worky reasons. It's blue and TBH sometimes it's just nice to watch the sand collecting up in a heap and then falling down in a wave. But if you're not looking for a visual aid or something that won't make a lot of noise in an already noisy office there's a load of free timer options. I also have a reminder on my phone to take my multivitamin (it interferes with my meds if I take it at normal med times).