Notes
Ran most of it at 12.8km/hr and sped up at the end. Was pretty gone at the end but not amazingly so. Had I been able to run free rather than treadmill-controlled then I think 23 mins was there for the taking - although probably couldn't have ran so fast if not on the flat, flat treadmill anyway.
Heart-rate shows there was more to give so that record may not last very long.