The longer the distance run, the more women have an edge over their male competitors. Yet, the longer the distance, the less likely women are to start the race.

In this engaging personal account, writer and sport scientist Jen Benson looks at the science and hidden history of ultramarathon running, and details her own attempts to finish a 100-mile race.

Jen lays bare the intensity, unexpected humour, and profound personal sacrifices that define the world of ultra-running, and delves into the fascinating science of ultra-endurance performance. Interweaved with this are the untold stories of trailblazing women from the last four decades, including Jasmin Paris, the first female finisher of the Barkley Marathons; Eleanor Robinson, the first woman to complete the 153-mile Spartathlon race; and Courtney Dauwalter, widely regarded as the greatest female ultra-runner of all time.

A testament to the feats of women that challenge the very limits of human capability, this is the remarkable sporting history of extreme performance hitherto untold.

Jen Benson is a runner, writer and PhD researcher exploring the psychology and philosophy of running. She has completed over 50 marathons and the UK Ironman and Ironman 70.3 triathlons. She is a qualified podiatrist with a master's degree in sport & exercise medicine. With her husband, she has co-authored several books including Wild Running, Short Runs in Beautiful Places and The Running Bible.