Just go for it Bats. Can't see them rejecting a postal entry unless it's full.
It was good last year as we went up for 3 days, & we spent the Sat at the Pleasure Beach. 
It's one for all abilities too. Think I beat something like 522 people! Good atmosphere with a live radio show & commentary.
Have you actually done any running in the past month!!?? When are you next going to Heaton? I'm getting drawn to the Woodbank park one too. Nice to have a change.