TWO brothers are going head to head in the marathon.
Terry Lee, 34, a DJ from Great Leighs, and Billy Hinken, 30, an insurance consultant from Chelmsford, are raising money and awareness for East Anglia's Children's Hospices (EACH).
The brothers will be running together, and sibling rivalry is coming to the fore as the day draws closer.
Billy said: "After sharing a bedroom with him for 15 years I don't like doing anything with him, apart from commiserating him on his inevitable defeats to me."
Terry added: "If he beats me I will never live it down. My mum said it's comparable to Mark Wright versus James 'Arg' Argent from TOWIE."
Terry said they wanted to help a local children's charity as "charity begins at home".
Billy added: "If people are willing to give me cash I'm willing to put my body on the line, a few hours of pain can't compare to what some families go through."
So far Terry has raised £65, but is hoping to raise £500 in total. Billy has also raised around £100 and is aiming to raise as much as he can.
When asked about training, Terry said: "I've been running through the mean streets of Great Leighs with kids and dogs chasing me like Rocky Balboa and jumping on the steps of the village hall."
