Run a marathon? Try 100 in 100 days

"Everyone tried to put me off at first - people just didn't believe I would actually do it," Cox says. But on 26 October last year, she set off from the Attari-Wagah border between Pakistan and India, bound for Kolkata, just a few miles from where her father Deric was born. She stayed true to the route, which meant there were sometimes days when she ran 42km along a highway "which was boring as hell" but other days were through nature reserves, along canals and through farmers' fields. …