Crossing the finish line in a parkrun event couldn't have been sweeter for mum-of-two Cheryl Herrieven.

It not only capped off a 100km challenge, raising £1,800 for dementia research, but it was her 40th birthday.

Mrs Herrieven, from Thorpe Hamlet, took part in the event last Saturday with family and friends at the city's Eaton Park. She decided to fundraise for Alzheimer's Research UK after her mother was diagnosed with the disease earlier this year.

Mrs Herrieven said she had never done much running until she took up the challenge. She said: 'My fitness has improved greatly, I can run 5km without stopping now. I saw Running Down Dementia advertised on Facebook in July and signed up. I realised if I did 10km a week I could fit it in by my 40th birthday.'

Mrs Herrieven said she had seen first-hand the effects of Alzheimer's, and knew how important further research into the disease was.

She said: 'Over the last few months there have been noticeable changes and I realise now that the signs have probably been there for a number of years. I worry too that my children may, one day, experience the same as I am with my mum with me, but all I can do is make the most of now, create memories and do my little bit towards raising money for research into this cruel disease.'

Kenneth Foreman, sporting events manager at Alzheimer's Research UK, said: 'We are blown away with how quickly Cheryl has run 100km and raised such a huge amount.

'There are 850,000 people in the UK with dementia, including nearly 15,000 in Norfolk. Alzheimer's Research UK is funding vital research which stands the best chance of finding treatments and preventions for dementia.'

To donate to Mrs Herrieven's cause, visit running-down-dementia.everydayhero.com/uk/cheryl-4