YEADON marathon runner Ben Thackwray is a man of extremes.

Last year he overcame searing 120 degree temperatures when crossing the Sahara Desert in the gruelling six-day Marathon des Sables.

Now 27-year-old Thackwray, a statistical business analyst, is preparing for a Polar expedition thought to be three times as tough as his desert adventure.

Going from one extreme to the other Ben is in training to attempt an unsupported speed crossing of Greenland and is aiming to break a few records along the way.

The fastest ever crossing was just eight days for a distance of 550KM and was set by a Norwegian over ten years ago. Ben is hoping to run his way across Greenland in around ten days.

He said: "Crossing the Greenland ice cap is a major undertaking in itself and is regarded as one of the three classic polar adventures (the others obviously being to the north and south pole).

He said: "What I''m trying to do is adopt a modern day lightweight' approach born out experience of ultra distance marathons and aim to cross the ice cap as fast as possible. Hopefully in around ten days.

"The record is eighdays on ski by a Norwegian and was maybe supported i.e. didn't pull a sled - I hope to essentially run and be unsupported. For this kind of approach I'm going to have to gamble with the amount of food and fuel I take.

"I will also have specialist lightweight equipment which means losing out on extra added warmth. I will have to totally cut out any luxuries and may go pretty cold. Having said that I like the idea that I'm trying something new."

Crossing the ice cap was originally planned as training for the other two polar journeys which he hopes to go on in the future but when he delved deeper into the idea it took on an importance of its own.

He has been consistently training since the Marathon des Sables last year, and next month he will get cold weather experience and try his hand at sled pulling in Alaska when he tries to climb Mount McKinley.

Last year Ben raised money for Facing Africa, a charity devoted to the treatment and prevention of Noma. And he intends to raise money for charity again when he crosses the ice cap in about ten months tim