As we near the end of the challenge, I'm not feeling so anxious about pulling a muscle or something, so I was happy to push for a 10K on this day's run. 

This was pretty brisk by my standards. I've never cracked a sub-60 10K but this was by far the closest I've got, so I don't feel that it's impossible. My 10K route is much nicer than my 5K one, with only a couple of road crossings and some nice long straight intervals over 2 - 2.5K. It's also mostly on the flat.

I spent the first bit of the run ...