- Runners must cover 230 kilometres in 7 days, including a full marathon stage and a non-stop stage of 80 kilometres in under 40 hours
- Temperatures soar as high as 125�F, dropping to freezing at night
- Competitors have to carry all their own food and gear for the whole race. Only 9 litres of water per day and an open-sided Berber tent are provided
- The terrain varies from rocky plains and lake beds to sand dunes
- Many fail to finish