The first 100-year-old to run a marathon, Fauja Singh, is also the first Sikh to be the main character in a book from a major publisher. Written by Simran Jeet Singh, the book tells the story of Fauja Singh including his 2011 marathon which made him the oldest person documented as having completing the distance. At 109 years old, Singh is still going strong, although he’s since retired from marathons. The book chronicles his entire…