I tried again to do a 21.1 km (half marathon) tempo run tonight. Coach Brian suggested going out relatively slowly for the first 10.5 k. The weather was much cooler than last week when I had to bail after 16k (at 24 degrees). Today it was about 13 degrees and so I wasn't overheating in the least. I wore a long sleeved running shirt and my running shorts, but it wasn't cool enough for ear-muffs, and not warm enough for short sleeves. The wind was light -- mostly from the west. I was targeting 5:22 per k for the first 10.5 kilometres and 4:52 for the last 10.6 kilometres. Here are my splits:
5:07 (500 m.)
4:37 (600 m.)
So I did 21.11 kilometres in 1:45:44 for an average of 5:01 per kilometre. I felt strong the whole way, as you can see from the improving times as I neared the end of the run. Heat was absolutely not a factor. My average speed for the fast portion of the run was 4:47 per kilometre -- but I know I could have gone faster for longer. So 1 week later a very successful run after a crappy run a week earlier. Goes to show that the weather makes a huge difference!