[frereubu]

They're pretty different in my experience (used to take LSD, run instead these days). LSD can be different things to different people, but for me it was a really intense experience, where everything was really vivid and alive. I think I get the runner's high you talk about, but it's much more meditative and (for lack of a less loaded term) wholesome. The comedown from LSD can be pretty grim, but running first thing in the morning improves my entire day.

Edit: Actually, if the comparison is microdosing I've never done that. But I'd take a run over microdosing any day, even if I could get guaranteed pharmeceutical-grade LSD on tap.