My first run a week after completing C25K was a good, 30-min effort on the treadmill.
I cop to a mental slump the week following W9R3, part work fatigue (29 12-hr shifts in 35 days), part disbelief that I could do it. I just rested for a week but stuck to my keto eating plan, deviation from which has proven a major stumbling block in previous slumps.
I don't feel that I'm out of the water yet as I have yet to hit solid ground for 30 min again. I cannot rid myself of the notion that real running is done on the road, park, track and trail. For me, the treadmill is a bit of a substitute for the real thing, a way to retain fitness by getting the old ticker racing until the weather improves.