The heat is on for Territorial Army Officer Captain Zayne Crow who is undergoing rigorous training to compete in one of the world's toughest long-distance running races, the 2009 Marathon des Sables, in aid of Help for Heroes.

This gruelling six-day endurance race, which sets off on March 26, covers 151 miles (243km) in intense heat across the Sahara Desert in Morocco through rugged terrain, over rough tracks, stony ground and sand dunes.

The Marathon des Sables is considered the toughest footrace on the planet with runners covering the equivalent of five and a half regular marathons during the six days, reaching a speed of between 3km and 14km per hour in temperatures reaching 120°F. In addition to the extreme mental and physical stamina required, the competitors also have to carry everything they will need for the duration on their backs in a rucksack (food, clothes, medical kit, sleeping bag, etc). Water is rationed and handed out at each checkpoint.

Captain Crow is no stranger to long-distance running competitions: "At the time I entered in March 2007 I was looking for a new challenge and the idea of Marathon des Sables was irresistible. The combination of the heat, desert terrain and having to carry all your supplies for the duration of the six days (seven for some) sounded perfect."

As part of her training programme Captain Crow has run eight marathons and two ultra marathons (52 miles) and regular cross-country runs carrying six to eight kg in her backpack. "I am feeling really strong and looking forward to this race. Because of the extreme temperatures and the weight I'll be carrying, it will be an immense challenge but I’ve put in lots of miles already and in terms of physical and mental fitness, I’d say I’m now in peak condition. Obviously my main aim is to complete the course and cross the finish line."

Colonel Peter Gilbert, Commanding Officer for 256 (City of London) Field Hospital said: "The Marathon des Sables is a truly awesome challenge – for most of us unimaginable. Captain Crow epitomizes the physical fitness, strength of purpose and determination typical of the British Army Officer. I know she will do herself and the Territorial Army proud."

When she is not running, Captain Crow is a Recovery Sister at the King Edward VII Hospital in London and has been a member of the Territorial Army for five years. Serving with B Squadron, 256 (City of London) Field Hospital based in Kensington, Captain Crow said that fundraising for Help for Heroes was an obvious choice. "Being a member of the TA and having completed a tour in Iraq, I could not think of a better charity to support. I have a just giving website for individuals to sponsor me through: justgiving.com/zaynecrow and I am also using Help for Heroes sponsor forms."