“SDW100”
Thames Path 100 starts at the really rather reasonable time of 10 o’clock, and is close enough to Richmond and Old Deer Park parkruns that it is possible to squeeze in a sneaky parkrun before the start. I didn’t, though I know of a handful of runners who did.
South Downs Way 100 starts at the really rather unreasonable time of 6 o’clock, and if you were to hang around to run Winchester parkrun, then you’d miss the cut off at the first aid station.
There is, for the very speediest runners, one glimmer of hope. The course runs past the start of QE parkrun and last year, the front runner made it to the park at 8:55am. It’s safe to say that I will never be that speedy, but it does mean that my crew, the wonderful Andy Bailey, has the chance to enjoy a leisurely parkrun before I make it to the park at about 10:30am, after which he will spend 24 hours waiting for me at car parks on the South Downs Way.
I do hope he’s remembered to pack a book (or two, or three).
abradypus 
Good luck and hope the weather is kind.
Thank you. All done. Weather wasn’t quite perfect but not far off it.
No book required, brilliant day – tough old parkrun!