Hundreds of people will descend on the Rye on Sunday morning to take part in the High Wycombe 10k and half marathon, but one man’s journey to the starting line has been longer than most.

Nick Kirby is on a mission to complete 25 marathons within a calendar year and Sunday’s race will be the 18th instalment of his challenge.

The London, Manchester, Brighton and Milton Keynes marathons, among others, have been completed on his route so far and the 13.1 mile course, taking the runners through Loudwater Wooburn Green, and Flackwell Heath, will be the next stage of his journey.

The 48-year-old, who is from Hampshire, is undertaking the marathons in order to raise money for the Cystic Fibrosis Trust after seeing the effect is has had on the 15-year-old son of one of his best friends.

Kirby has so far raised nearly £9,000 for the charity, having targeted the £10,000 mark when he undertook the challenge.

After originally being unsuccessful in the ballot for a place in the London marathon, Kirby applied for a charity place and in order to raise a sizable chunk of money decided to participate in a number of events.

Kirby said he found the exploits of comedian Eddie Izzard “admirable” after he completed 43 marathons in 51 days and that he felt doing something similar would help him to attract more financial support for the Trust.

Sam Carter, Regional Fundraising Manager at the Trust, said: “Nick is showing great determination in taking on these gruelling marathons, and his willingness to keep going and raise vital funds has been a great source of inspiration to all those affected by cystic fibrosis.

“The money raised will enable the Cystic Fibrosis Trust to invest in cutting-edge research and to develop better treatments. It will also provide support to those with cystic fibrosis and their families and help the Trust to drive up standards in medical care.”

Kirby’s hectic schedule will take in the New Forest marathon, the Loch Ness marathon, the Bournemouth marathon and the Amsterdam marathon, among others, after he completes Sunday’s event.

“Running is something I did when I was much younger, but not really to a good standard. I am a bit big so I’m better suited for rugby or rowing really, but not running - I do enjoy it though,” he said.

“I stopped running for many years and just did the odd half marathon. About five years ago I realised I’d become way too big and decided to do something about it, so I've been running ever since. Next stop – High Wycombe.”

The High Wycombe half marathon and 10k race begin at 9.30am and if you’re not signed up yet entry is £22 and £20 respectively for the events.

To sponsor Nick visit his Just Giving page here: http://uk.virginmoneygiving.com/fundraiser-web/fundraiser/showFundraiserProfilePage.action?userUrl=nickkirby