TWO ARMY college instructors will be taking on the heat of the Sahara desert next month, as they take part in a run dubbed the toughest foot race on earth.

Major Al Grant and Captain Tristan Burwell, instructors with the Army Foundation College in Harrogate, will be embarking on the Marathon des Sables in Morocco in April.

The gruelling race is 156 miles across the Sahara. Runners are exposed to burning desert temperatures which often exceed 50 degrees centigrade and night time temperatures which can plunge to zero.

The two instructors ran the Yorkshire Three Peaks at the beginning of February and completed a fell marathon on the North York Moors just before Christmas, but said preparing for the desert heat in North Yorkshire was difficult.

Major Grant, 30, said: “It has been difficult to prepare ourselves for the desert when it’s the middle of winter in Harrogate. We have to wear lots of layers of warm kit to make up for the lack of sun.

“It has meant a lot of very early morning starts for me and Tristan, and it’s lucky that we work together. ”

Captain Burwell, 30, who is a company second-in-command, said: "Al and I are both in the 9/12th Lancers and we served together on two extended tours in Helmand.

“The idea to do the Marathon des Sables was born in June last year as we neared the end of the second tour, when we and two other officers from our regiment decided that we needed a new challenge post-Afghanistan.”

They will be raising funds for ABF, The Soldiers’ Charity. To donate visit: www.justgiving.com/2015MDSTeam

Only 1,500 people from around the world are selected to take part in the competition. They also include electrician and runner Steve Woof, from Ingleby Arncliffe, near Stokesley, North Yorkshire.