When I was young, I exercised for at least an hour 5 times a week. Walking, aerobics classes, not sports. I also did yoga for 45 minutes almost every day.
25 years ago I tore cartilage in my knee and I've become less and less active every since. I'm a certified couch potato now.
I think that when I was young I had more hypomanic episodes and the exercise helped out - it helped burn off some of the hypo energy. Now I'm more depressed than hypo. Is it due to my exercise level changing or something else? I really don't know.