CHARTERED surveyor Ed White will be putting his passion for a sporting challenge to the test when he takes part in what is billed as the toughest foot race on Earth.

The 33-year-old father of two, who lives near Lydeard St Lawrence, is in the final stages of training for the gruelling Marathon Des Sables that will involve running a total of 150 miles over seven days across the Moroccan Sahara.

Ed and university friend Charlie Prentis will have to endure temperatures of between 40 and 50 degrees centigrade on the trek, whilst carrying kit weighing around seven to ten kilos.

With a field of an estimated 1,000 runners, Ed is hoping to finish in the top 250.

But he is not underestimating the punishing nature of the event, which will mean running the distance of a double marathon on one day and a marathon on the remaining days.

Whatever the outcome, Ed and Charlie are on track to raise a total of £20,000 for two of their favourite charities - Parkinson's, Charlie's choice because his family has experience of the disease, and children's heart charity Tiny Tickers because Ed's nephew was born with a severe co-arctation of the aorta and needed life saving surgery.

"The amount of money we raise for these two causes is really important and the total stands at about £17,000 so far," said Ed.

"It was only when I had children of my own that I truly understood the fear, pain and anguish that my sister and her family had to endure.

"If I can help just one other family avoid the same experience I will have achieved my goal."

Although they are both keen sportsmen, Ed and Charlie have only completed one marathon previously - Florence in 2004.

"After that we vowed never to run that far again," said Ed.

"But time is a great healer."

Ed has been using the Quantock Hills as his training ground since last summer in preparation for the event, which begins on April 6.

The commitment has been tough in itself as his wife Emily gave birth to their second son just six months ago.

And with a three-year-old already, there has not been a lot of time to spare.

But Ed said he had realised over the past year that the Marathon Des Sables was as much a mental battle as it is physical.

"It relies as much on self-discipline and preparation as it does on physical endurance.

"I don't think I could ever be ready for what is to come but I have a mixture of excitement and fear and, to be honest, I've been thinking about it for so long I just want to get on with it now."

Photo: Steve Guscott