On March 27th, I'm going to the sahara to run the Marathon des Sables, a 155 mile footrace ran over 6 days, in temperatures of around 42 degrees. I will be self sufficient throughout, carrying my own food and equipment. People have died on the course, limbs get broken, and no one escapes the blisters. In training for this event I have heard many useful words of advice, but the one that stays with me is that you need to understand what your motivation is.  When you're halfway through the night stage, with feet like corned beef, a swollen tongue and a dehydrated brain, you are faced with the option of pulling out a flare and calling for a heli-vac to take you out of the race, or carrying on through the pain. If you don't have the right reason for running, it's too easy to drop out. My reason is Blossom, my cousin's daughter, who was born without functioning kidneys. She has just received a kidney, transplanted from her dad. I have seen her undergo an amazing recovery, and have been told by the doctors at  Great Ormond Street about how Blossom's condition could one day be preventable, but as yet there is no cure for Kidney disease. That is why I would like to raise money for Kids Kidney Research - a highly worthwhile and personally relevant cause.