The London Marathon attracts elite athletes to the capital every year, who showcase the pinnacle of physical fitness.
But we all know what the big day is really about - the hilarious outfits.
Here are some of the best on a day that saw 36,500 runners start the race and and impressive 34,600 reach the finish line.
We're pretty sure taking public transport is banned...
Marathons are even harder when you're smurf-sized.
Humphrey the camel looks surprisingly hydrated as he enters the final stages.
After 20 miles or so, that mankini must really start to chafe.
Why isn't Prince Philip making an inappropriate remark?
One way to make sure your friends spot you on the telly.
The self-explanatorially-named Mr Testicles in action.
That rarest of sights - policemen roaming the London streets.
This man has earned a celebratory can of Irn-Bru.
If those gorillas had simply eaten the banana they might be in better shape.