Lisa Millard is facing one of the most gruelling tests in the world to help soldiers who have lost limbs.

Mrs Millard, 37, of Barton Park in Marlborough, has signed up for the Gobi Challenge 2010, involving seven marathons in six days in the searing heat of one of the world’s most arid deserts.

She will fly to China for the run across the Turpan Basin, the second lowest place on earth, where temperatures top 40 Celsius, next June.

She has never run a road marathon, but Mrs Millard, who works at Monsoon in Marlborough, is an experienced off-road runner.

In June she took part in Man v Horse in Wales, in which 400 runners competed against 49 horses across the Cambrian Mountains.

She said: “It was really warm and some of the bogs were thigh deep. It was brilliant fun.”

She agreed to take on the Gobi desert at the suggestion of her business partner, Lee Davies, with whom she runs the mountain bike event organisation Muddybaks.

She contacted Chris Todd, of Bromham, who completed the Gobi Challenge last year. Mrs Millard said: “Chris was brilliant. His advice was so valuable.”

As well as running 26 miles a day, with a double marathon on the last day, she will have to carry all her supplies and equipment.

She said: “I intend to travel as light as possible. I will have a good supply of dried foods – and jelly babies for an instant sugar rush.”

She has husband Shaun’s full support, but admits: “My husband thinks I’m mad. I think he would like to run with me, but he can’t take the heat or the distance.”

Mrs Millard will be raising money for the British Limbless Ex Servicemen’s Association.

She said: “I am full of admiration for our servicemen who put their lives in danger in Afghanistan and especially those who soldier on despite losing limbs.”

Potential sponsors can log on to www.justgiving.com/lisamillard go bi2010