'It blows your mind how capable the human body is'

Kim Ludlow said when she got a spot in the London Marathon she thought running the distance was "unimaginable"

A woman preparing to run Sunday's London Marathon in memory of her son has said it "blows your mind" that she is taking part.

Kim Ludlow's son Bruce died at 38 weeks after she was in hospital for two weeks and he caught an infection.

The 54-year-old, from St Neots in Cambridgeshire, is raising money for the charity Sands, which supports those affected by the death of a baby.

"You just can't imagine it and how that's affected me; it's been quite significant," she said.

Kim Ludlow said she will have something with her to remind her of Bruce when she running the marathon

Ms Ludlow, originally from Kettering in Northamptonshire, said the iconic 26.2 mile (42.2km) race in the capital had "always been a challenge of mine".

"I lived in London for 13 years and was fortunate the marathon ran at the bottom of my street and I was amazed at all the different sizes, shapes and ages of people running past," she said.

She said she "just thought now's the right time to do something for Bruce. He would be 20 this year".

"He's always in my thoughts and sadly it's something that still happens to lots of young families," she said.

• How to follow BBC coverage of the London Marathon

She choose Sands as it was "a charity that's close to my heart" after it helped her following the death of her son.

"The run is 100% all about Bruce, but it's also that positive light of recognising the Sands charity," she said.

Ms Ludlow said she could "barely run" 5km (3.1 miles) when she started training but was now up to 20 miles (31km).

She said: "Anyone can do it. It blows your mind how capable the human body is, providing you've got the right training and the right advice and you're not pushing yourself and you're doing the right thing, and you're eating well.

"Half of me is really excited and the other half of me is really anxious, but I just can't wait to enjoy it."