Run 59:00  8.1 km (7:17 / km) +350m 5:59 / km
The upper hamstring twinge from late yesterday made its presence felt overnight - it's never a good sign when something hurts enough to wake you up during the night. I wasn't particularly confident, but it felt sort of OK warming up on the flat so I decided to start and see how it went. Knew within the first 1.5km that I was in trouble, but thought I'd get to the top of the hill (in this part of the field, you mostly have to walk the steepest parts whether you like it or not, because of congestion on the single track) and see if it improved at all once over the top. The answer was that it didn't really and was uncomfortable on any sort of slope both up and down - felt like the sort of thing that I could probably struggle on with if it really mattered, but not worth it for what was clearly going to be a poor time, even compared with expectations.
It's getting frustrating that a new injury seems to pop up each time it looks like the last one's fixed. (It's also a pity to waste conditions as good as you'll ever get in January). I know that's part of getting older but not everyone falls apart. Seeing the physio tomorrow so will see what she thinks.