Only 10K today, and the weather was decent for December, with temps of 27F (-3C) and calm. I wore my balaclava but got too warm and had to take it off.
I started off feeling a little heavy-legged but with plenty of energy. About 7.5K I started to feel the effects of yesterday's 12K fartlek and it definitely slowed me down going back up the gentle hill. Up until then I'd been keeping a 6:13/km pace, but my total today was 1:03:08 for 6:19/km with ave HR 142.
Garmin connect data here.