Who are Dave Scott, Mark Allen and Chrissie Wellington? Let's take the first two for starters, as indeed the Americans were as they lined up for the 1989 Ironman World Championship in Hawaii.
Scott had won the gruelling triathlon – a 2.4-mile swim followed by a 112-mile bike ride, topped off with a full 26.2-mile marathon – six times in a row. Allen, four years his junior, had come second twice.
For the next eight hours they could hardly be separated, until with less than two miles to go Allen broke free to win by 58 seconds in a then-record 8hr 9min 14sec, the third man trailing home over 22 minutes later. Scott never won again, while Allen went on to equal his six victories.
Matt Fitzgerald knows both athletes well, and explores their backstory in detail as he builds up to the drama of that epic duel in the sun. But the narrative pace of the book is diminished by lengthy digressions into the science of distance running.
While interesting, these explorations of the latest psychological and physiological research would have been better packaged as separate chapters. Nevertheless, his account of how and why these two men were driven to push themselves through pain unimaginable to most of us remains absorbing.
As for Wellington, she was once trained by Scott, who must have done a good job because she has won the women's Ironman World Championship four times in the past five years (she missed 2010 because of illness), and holds the world record. What's more, she's British, having been born and brought up in Norfolk, though you could stop a lot of people in the street before finding someone who has heard of her.
Let's hope her autobiography, A Life Without Limits (Constable, £18.99), published later this month, brings her more recognition. She deserves it.
Published in paperback by Quercus, £12.99