Okay, I had my heart set on racing tomorrow and setting a PR for the half marathon, but now that I think more about it, I have to fit in my 20 miler. The half marathon will be done at a marathon pace, which will give me the proper stimulus and let me feel what MP will be.
Looking at it, it's a smart move as my small leg injury (which has totally vanished) resulted in me missing my last long run last weekend and a few speed sessions. Having the last long run three weeks out from marathon day is the perfect way to jolt my body back into some sort of top fitness.
My feeling is either I run 5K right before the race and do 6K after the race or just do the race and complete it with another 10K.
The aim will be do go for 4:37 kilometres, which should feel quite comfortable for a good while, I'm thinking.