Derek Earl has completed the equivalent of 180 marathons in 27 years since catching the running bug.

The 67-year-old's amazing feat, which includes 19 London marathons, means he has notched up more than 4,700 miles - not including the 50 he runs every week just for fun and to keep in shape.

But now Derek, of Manor Avenue, Hassocks, is about to set off on an even bigger challenge - walking 500 miles across the Pyrenees and into Spain in 30 days for charity.

He will be joined by Paul Green, 36, from Haywards Heath, who he met while walking from John O'Groats to Land's End in 2001.

Derek said: "The first part across the Pyrenees is 15 miles and they reckon it could take 12 hours because it's so steep - 4,000ft up then a steep path down the other side.

"We have talked about what will happen if one of us succumbs to the distance. You can make your way by bus but it will take an awful lot to stop us because we are so determined to get to the other end."

The Camino Santiago, or The Way Of St James, is a pilgrims' walk named after the disciple James, who was one of the first apostles.

He was martyred in Jerusalem in 44AD but his friends managed to sneak his body out from under the nose of Herod Agrippa and put him on a stone boat headed for north- west Spain.

After a week-long journey, his body arrived on the Galician coast and other disciples buried the body inland at Santiago de Compostela.

The remains lay undiscovered until 813AD when a hermit was mysteriously led to the site.

A small chapel was built there a few years later and from then on pilgrims made long journeys to pay homage.

More than 1,000 years later, Derek and Paul are about to do the same journey to raise money for the Leo House Children's Hospice Appeal.

Their inspiration comes from a little girl called Emma Vigar, from Hurstpierpoint, who died from cancer in 1999.

When doing long-distance challenges, Derek often takes along a three-wheel buggy full of provisions. He intends to take it on this trip, which begins on Friday He said: "There are all sorts of things along the route.

"You can take a pebble from home and leave it on this vast pile that has been built up over the years by other travellers.

"We will be staying in basic refuges and monasteries.

"We want to do it as the pilgrims did it.

"It can be too hot, too cold, too wet or too windy but we are optimistic it's going to be just right."

Derek began running when he was 40 to get fit. What started as a leisure pursuit quickly turned into a passion and he has been pounding the pavements ever since.

He said: "I took up running and over a couple of years it developed into an addiction.

"It's great because it gives you a sense of well-being, you can eat what you like and it helps keep your weight down."

Anyone who would like to sponsor Derek or Paul should email Ray Vigar, of the hospice appeal, at ray.vigar@virgin.net