Guinness World Records has teamed up with the Virgin Money London Marathon for the ninth consecutive year to offer official record verification on the day of the iconic race.

Taking place on Sunday, an incredible 55 Guinness World Records titles are set to fall, with runners completing the 26 mile run in a variety of costumes including a dinosaur, chain mail, a two-person horse, plants, film and book characters and a fire engine.

London Marathon 2016 runners collage

Here five runners share the reasons behind their upcoming attempts:

Ben Evans – who told us “I run like a T-Rex” – is attempting to set the record for the Fastest marathon in a full body dinosaur costume. This is the 37-year-old’s fifth London Marathon and he is running for Terrence Higgins Trust to increase help for HIV patients and promote research and awareness.
David Cooke from Kent has set his sights on the Fastest marathon dressed in chain mail title in support of the London Air Ambulance (London Freemasons Pledge). Last year he ran three marathons in three consecutive weeks. He hopes to set the best possible example for his children and inspire them to never shy away from fighting to achieve their goals.
Fraser Barrett, Charlie Reynolds, Oliver Smith are attempting the ultimate team challenge – the Fastest four legged marathon (male). This will be their first ever marathon. The idea originated over a few drinks at the pub, but they are totally serious about achieving the title. The friends have all experienced how a stroke can affect family and friends, so they are running in support for the Stroke Association which has cared their relatives and raises medical research and awareness.
Read more about Sunday's Guinness World Records title attempts here: 2016 Virgin Money London Marathon preview: How 55 Guinness World Records titles are set to fall