Hi! I had the Mirena placed October 2007. It was removed November 2009 (after about 2 years in). So my 5 year date would be this fall, I guess. Interesting.
I started running by only going around my block, mostly walking with a bit of jogging. I would come home feeling dizzy and spacey (at least more so than I had before I left). I didn't feel like it was helping me really, but a voice inside me has been telling me to do this. So I just kept doing it, 2-3 times a week, increasing as I was able to. Sometimes I would go out feeling lousy with my symptoms and come back feeling no better, but I rarely felt worse, except for normal tiredness after running. After time, I could feel myself feeling stronger. It seems to keep many of my symptoms at bay, better than anything else I've tried anyway.