Or that's what I thought when I went out this morning. It was cold, even thought it was -1.
Ran with my heart rate monitor for the first time in a long time. Did a 15K city route (to Bloor and back then out to Jarvis and back). Ran for 1:16, according to the monitor, with an average rate of 156 (yes on the high side) and I was in the aerobic zone for 46 minutes. I spent most of the other minutes above 85%