Distance running and trail running can be addictive - at least that is what I my trail running friends tell me. I run 5 or 6 days a week from mid-May to early November. Most of my miles are on the road except for the summer cross country runs at John Hunt park. I guess you can consider that a trail, but it is a not fun one. The rest of the year I try run 3 days a week.
I don't race much anymore because most of the good races are either during deer or turkey season. The longest races I do anymore are the Cotton Row 10k and Hellen Keller 5 mi. I have ran a 1 mi, 10k, and half-marathon in a 36 hr period (Friday night, Saturday morning, and Sunday morning). It sucked in real-time and in hindsight, so I don't feel compelled to do any other longer distance just to say I did it. But I do enjoy running just to run.