Apryl Hammett, a 54-year-old librarian from Chelmsford, is chasing the rare Triple Crown of marathons by completing her 100th road race at Sunday’s London Marathon. The milestone would make her the fifth female to achieve 100 road, trail, and ultra-marathons, a feat requiring 300 total races. Hammett, who has already conquered over 100 trail and ultra-marathons since starting at 25, credits her Alzheimer’s Society fundraising for sustaining her drive. “The support from families affected by dementia keeps me going,” she said, highlighting the charity’s impact.