Saturday Speed

12K @ 5:00 pace with Fartleks at 4,5,6,7,8,9 and at 10.1 K I began a cool down with a 400 meter fartlek at a 4:45 pace gearing down to walk the last .5K.   HR was lower ,  didnt break 140 until I hit the 9K mark.  Cadence was higher ... weird and the ground contact time and vert osc were a touch improved ... no idea why although I was running with a fan in front and behind and I was shirt free but thats more or less the way I did it last weekend on mids ... go figure!