Toughest Race on Earth

James Cracknell, double Olympic Gold medallist, is about to face his greatest ever test of endurance. He's rowed the Atlantic, conquered the Antarctic and won two Olympic gold medals. In this latest challenge James will be putting his body and his reputation on the line in setting out to conquer the toughest race on earth. It is called the Marathon des Sable (MDS), six back to back marathons across the Moroccan Saharan Desert where not everyone will finish, but typical to his ambition and drive James doesn't just want to finish the race, he wants to be in the elite top 50. The aim of the MDS is to test the limit of human endurance. Every year 1000 athletes from more than 30 nations run over 250 km in one of the most inhospitable places on the planet. Will James Cracknell find his way out of the dark, be able to add the Sahara to his role of honour and what challenge can he set himself next?