article_snippet.sent: Tough: In the Marathon des Sables, athletes have to carry athletes provisions on athletes back and sleep in tents .
article_snippet.sent: The course is a six day race and there is only one rest day.
article_snippet.sent: Competitors must carry all Competitors provisions for the whole race on Competitors back.
article_snippet.sent: Temperatures in the Sahara Desert can reach 50 degrees during the day and more than 40 per cent humidity, while dropping to below freezing at night time .
article_snippet.sent: The team hadn't done any mountain climbing in The team training. '
article_snippet.sent: The team were eight or nine hour days running in that heat. '
article_snippet.sent: It was sweltering and rower James Cracknell also had to go through sandstorms.