Paula Jane Radcliffe MBE is a former British long-distance runner. She is a three-time winner of the London Marathon, three-time New York Marathon champion, the 2002 Chicago Marathon winner and the 2005 World Champion in the Marathon from Helsinki. She was previously the fastest female marathoner of all time, and held the Women's World Marathon Record with a time of 2:15:25 for 16 years from 2003 to 2019 when it was broken by Brigid Kosgei.

A half marathon is a road running event of 21.0975 kilometres —half the distance of a marathon. It is common for a half marathon event to be held concurrently with a marathon or a 5K race, using almost the same course with a late start, an early finish or shortcuts. If finisher medals are awarded, the medal or ribbon may differ from those for the full marathon. The half marathon is also known as a 21K, 21.1K, or 13.1 miles, although these values are rounded and not formally correct.