NEW YORK :Dutchwoman Femke Bol announced on Friday that she is switching from the 400 metres hurdles to the 800m and will start competing in her new event next year. While the 400m hurdles world champion has often played second fiddle to the United States' world record holder Sydney McLaughlin-Levrone on the Olympic stage, Bol has collected five straight Diamond League titles in her signature event. "I’m really excited to share the next chapter of my career," the four-times Olympic medallist