The Marathon des Sables, known as the toughest footrace on earth.

Competitors have to take on six marathons in six days across the Sahara desert, covering over 250km, in temperatures rising to 50°C.

The rules require you to be self-sufficient, to carry with you on your back everything except water that you need to survive.

Our aim is to raise at least £250,000 for Walking with the Wounded.

This podcast is the story of those taking part in the future and of those with experience from previous years.