A keen cyclist is kicking his hobby up a gear for a 330-mile charity bike ride to France.

Iain Harper will be setting off on Wednesday to ride from London to Paris in aid of the Alzheimer's Society.

The 52-year-old from Thetford will be among around 120 people leaving from Blackheath Common for the four-day ride, which will cover 328 miles. Together the cyclists hope to raise £250,000 for the charity.

He was inspired to undertake the challenge after his brother-in-law, rugby player Alan King, was diagnosed with Alzheimer's aged 56.

The former fly half for Newark RFC and Nottingham had retired to spend more time with wife Fiona at their home in Lincolnshire when he began to develop the degenerative disease.

Mr Harper said: 'The disease is the most tragic, awful thing. It robs people of their loved ones. It just makes me so angry to see.

'Back in the 1980s Alan was a very good rugby player. He was diagnosed at quite a young age and it has progressed quite quickly. For my sister it is like having to look after a child all over again.'

Mr Harper, himself a former rugby player, got into cycling around eight years ago.

He regularly cycles between 35 and 70 miles with friends and took part in a ride from London to Brighton for the British Heart Foundation two years ago.

Ahead of his momentous new challenge, he said the 'nerves are starting to set in'.

'There are a few butterflies, but thinking about why I'm doing it they soon dissipate.

'I did the Boudicca Sportive a couple of months ago and pedalled over 100 miles in a day. It's all in the training,' he said.

The production director at Pegasus Profiles in Thetford said he has received sponsorship and support from his colleagues as well as from friends of his sister and brother-in-law in Lincolnshire.

He added: 'My wife Debbie has been supportive of me being out and about so often.'

To donate to Mr Harper, go to www.justgiving.com/Iain-Harper4

Are you taking part in a sports challenge for charity? Email newsdesk@archant.co.uk