For someone who describes themselves as “not really a runner” taking on the Marathon Des Sables could be called the stuff of nightmares.

But Kevin Duffy from Banstead is doing just that, and starting on Friday he faces a 156-mile race over seven days in the searing heat of the Sahara Desert.

Moreover, despite having 10 years experience of ironman triathlons, Duffy is no spring chicken at 53 years old.

While not being scared of what lies ahead of him, the electrician by trade has respect for the conditions and while he cannot wait to get started, he is also looking forward to getting it over and done with.

“I have done numerous ironman triathlons comprising a 2.5-mile swim, 112-mile bike ride and a marathon.

“But this will be the first, and probably the last time I shall attempt the Marathon Des Sables, “The main difference between this and ironman is that with ironman you can push yourself for a day, knowing you can have a shower and go home and spend the next few weeks recovering.

“But this is push yourself for a day, sleep rough in the Sahara desert, and then get up and do it all over again, and you repeat for a week.”

Duffy, who has spent time training on the sandy beaches of Lanzarote, added: “It is going to be extremely tough, even the training has caused me no end of injuries and niggles I have never experienced before – I anticipate the actual event will be two or three times as bad.”

Competitors, who must have a full ECG scan signed by a doctor before starting, face three marathons over three days, followed by a double marathon, and finally a half-marathon.

They must carry all their food, bedding, navigation equipment and daily water allowance of 3.5 litres – it is also compulsory to carry a venom pump in case of snake bites.

The race is point to point, and at the end of each day’s run, the organisers erect a bivouac for competitors to sleep under.

Duffy said: “I am not prepared for the double marathon. I think I will be reduced to walking at that time and it will be quite a distance to cover, and even now I find it quite difficult to get my head around.

“I am not really a runner – I am more like a rugby player, I am quite big chap. We have to take 2,000 calories of food per day, and I normally need more than that so I am anticipating losing weight.”

He added: “I know people who have done it a few times and they say they are still not prepared for the conditions.

“I am not scared, but I am respectful of what the marathon can do. I cannot wait to get started, but I am also looking forward to it being over.”

Duffy, pictured, is running for the Alzheimer’s Society, and you can donate via his justgiving page at justgiving.com/Kevin2912.

Some Marathon Des Sables facts

The race starts on April 3 and comprises: 

Day 1: 22 miles
Day 2: 25 miles
Day 3: 22 miles
Day 4: 51 miles
Day 5: rest
Day 6: 26 miles
Day 7: 10 miles

Temperatures in the desert can exceed 50C and the Sahara is home to more than 20 venomous snakes.
There will be: 

500 support staff.
52 medical staff.
120,000 litres of water.
100 all-terrain vehicles.
2 helicopters.
1 Cessna plane.
23 buses.
4 camels.
6.5km Elastoplast.
2,700 Compeed gel plasters.
19,000 bandages.
6,000 painkillers.
150 litres of disinfectant.