I have applied for the ballot to run the London Marathon several times, I have not yet been one of the lucky ones who've been offered a place but this year (2026) my daughter got a place - first time entering the ballot.
She did tell me that there are people who choose to run the whole marathon at midnight before the race, the other way around. Nothing official, just for all these people who didn't make the ballot or got a charity place.
I decided to go for it, I had never run a marathon distance before but I am a runner on and off, furthest ever was 16 kilometres.
I had started messing with a no code app builder for my own 'life organisation' and thought, it'd be really useful to have an app on the night of the reverse marathon that showed me the route, distance, nice things to see along the way and most importantly - any 24h shops open along the way 'just in case'.
I created the app and then reached out to the admins of the Reverse marathon Facebook group that had done this many times before, had lots of good info and FAQ's and said that, perhaps other people would like to use my app too.
The app is still available here (although the lovely people at Reverse marathon asked me to use it for their 'DBS on tour' info - which I set up to feed from a spreadsheet they can populate to show more info).
If I get in to the 2027 London Marathon I wont need this app myself but I probably will update it for those who run it (and - let's be honest, I'm probably one of them).