What do you do if you don't get a place in the London Marathon? Simple: you run the course backwards in the early hours of the morning.
Hundreds of runners got over their disappointment of missing out on the chance to be part of the official event, instead taking an even more hardcore decision of starting the gruelling run before sunrise.
The dedicated runners started in Central London at either 2am, 3am or 4am, depending on how their predicted finish times, and then ran to the finish line at Greenwich.
Participant Jess Roper told ITV News: "It’s always more fun to run in a group, and I heard about nohtaram eht on social media, so thought it would be a good way to meet other runners, have a cool experience and get my training run in!"
Adjusting your body clock for such an endurance event is not easy, meaning it's early to bed and rise.
"It’s not as hard as you’d think! I went to bed at 8pm, so I had managed to get a bit of rest. It’s difficult to get out of bed at just gone midnight to get over to the meeting point but once you’re there the adrenaline kicks in and you just go for it."
There could be a sense of eeriness pounding the streets of London with few people about but Jess took it all in her stride, before becoming part of the crowd for the official marathon later.
"It’s a really different spirit to doing the regular marathon. There are no crowds to cheer you on, but you end up chatting much more to the other runners and you’re not fussed about getting a ‘time’ so it’s more sociable. It’s more like you’re part of a team.
"My group all went to breakfast afterwards and then hung out and cheered on the actual marathon runners afterwards, so I felt like I made lots of new friends."
Next year, even if you do miss out on the official marathon, there's still chance to take part.