Not to be confused with parkrun (only a complete idiot would do that in their original ballot application), this is very much a one-off - a 5 mile run round the Olympic Park, ending in the Olympic stadium full of cheering supporters.
They've sent me a super-smug t-shirt to wear.
This will doubtless look amazing with my new Skins compression calf tights (otherwise known as "very tight socks") and shorts.
The packaging says "It's not like your sense of style falls asleep the moment your muscles go to work. Consequently Skins are also designed to make you look great."
It is all very exciting and once in a lifetime-esque. I'll be beating Paula Radcliffe over the Olympic finish line! Not that she's running on the same day as me, but still. And there'll be celebs doing it. Well, Princess Beatrice is running it anyway - here's hoping her crown doesn't fall off.
So, if you're watching the National Lottery Show on Saturday, look out for me (and find yourself something considerably better to do next Saturday night).