Hey !
I have struggled with restless legs since the very beginning of my AS journey. It's interesting you mention exercise, because that triggers mine as well. Here's the catch with me though. I also have been diagnosed with fibromyalgia and most recently found out I have severe reflux of both great saphenous veins in my legs. Nobody really knows what to attribute my leg symptoms to at this point because every diagnosis I have is from the pelvis down. So not only do I have RLS, but I also have painful, swollen, heavy legs.
I'm not a medical professional, but maybe you could try compression socks? I have to wear them for my veins, but I have some close friends that wear them who have AS just because they like the feel of the squeeze. I don't know if it helps with RLS, but mine has improved some since wearing them! Hopefully you'll get some more helpful feedback here!
All my best, Katie, Team Member