How would you feel if your life was suddenly shattered by a dramatic turn of events? Karen Darke, who herself was paralysed after a rock climbing accident, speaks to four remarkable people about how they managed to fight back and regain their lives.
Mark Pollock was about to sit his finals at university and embark on a promising banking career when he suddenly lost his sight.
Since then he's set up a business, rowed in the Commonwealth Games, forged a career as an international speaker and run marathons in the Gobi Desert and North Pole.
Paul Taylor was planning to run the Great North Run for the third time when he became paralysed after a mountain biking accident.
Less than a year after breaking his back, however, he completed it in his wheelchair.
In 2003 Anna Hemmings, an international marathon canoeist, was diagnosed with chronic fatigue syndrome and told she may never race again.
After two years of fighting the condition she is back at the very top of her sport.
At the age of 15 Stephanie Metcalfe was a teenage mother, a drug addict and living on the streets.
Ten years on she has fought back and now has two children, a forthcoming wedding and is about to go to university.