Why does running make me nicer?

This is a great question from one of the people I was just working with on a telemedicine visit. Does running really make me nicer? She actually said, "It's been really tough being injured, because it seems like when I can't run, I'm not nearly as nice as I usually am." Well, if you're anything like me, it probably does and that's what we're talking about today on the Doc On The Run podcast.