Let's be honest. Pre-war ultra-marathons weren't exactly a mass market competitive sport, and Rob Hadgraft may never outsell Rowling on this one.
But Arthur Newton is an intriguing character whose most famous legacy is the hugely successful Comrades Marathon between Durban and Pietermaritzburg. Anyone over the age of 38 can take heart from knowing that that's the age that Newton took up running. And boy, did he run - 25 miles a day in 1923 - the father of the long, slow distance, and awesomely fit into his late middle age.
Often a solitary runner, at first very shy and through his life always formal and reserved, a lifelong batchelor, there is something unknowable about Arthur Newton. What did go through his mind as he put in those vast distances and learnt how to suffer on the dusty roads?
Newton's original cause for running was a land dispute over native resettlement, and Hadgraft has a hard job to translate the cultural prejudices of pre-war South Africa for a modern audience. The reader may want to stick to the running - but the biographer does rightly leave you niggled that Newton's attitudes never changed with the times.
And so perhaps the most uplifting part is in Newton's advancing years. Happy to coach others to break his own records, delighted to see his sport thrive, a man of immense encouragement and hospitality. There's a vision for the well-lived sporting life.