It isn't a question of if I feel like running, it's a question of "is it Monday, Tuesday, Thursday or Saturday?"
That's the key. Certainly was the case when I was really working out before college. It was a loss of confidence in failing to meet the standard of an intense bodybuilding plan after a back injury that threw me off the habit at the time, but some sort of schedule if not a plan is what I probably need the most, as opposed to "do I feel like it today."
Well, the run is the only thing I don't max on-record, but being graded on my performance also means my push-ups are 90 degrees enough rather than 90 degrees and my graders are superior enough rather than CO.