Running a marathon is an incredible feat in itself - but some people like to make it even harder by dressing up in fancy dress.
This year more than 50,000 runners will tackle the London Marathon, setting off from Blackheath and finishing on The Mall.
A large majority of those running the 26.2 mile race will be raising money for charity, with many gaining entry on a charity place.
Every year tens of millions of pounds are raised by marathon runners and many have caught on to the idea that they might be able to raise more if they make their run as uncomfortable as possible by wearing outlandish outfits.
Fancy dress is also a great way of raising awareness about different charities and their work.
So we’ve rounded up some of the most inventive and frankly most uncomfortable-looking outfits over the years...