I totally agree that it can be hard to know what "healthy exercise" is. And I think a lot of people over-do it, even if they don't have an "official" ED. I am also someone who tends to do things to extremes, and exercise fits right into that category for me.

Trixielou mentioned walking and I now find that to be the healthiest exercise for me. I have 3 energetic dogs and we hike a lot every day, but it's not that obsessive or excessive type of exercising that happens when I run. I find walking to be the best form of exercise for me now.

Sorry about your knees ((((((trixielou)))))) I have issues with my Achilles from running.