The Norwegian Method of endurance training is the hottest trend in endurance sports. Norwegian athletes like Jakob Ingebrigtsen and his brother Henrik, Kristian Blummenfelt, and Gustav Iden have smashed records and grabbed medals in running, cycling, and triathlon. Their approach? Using lactate testing and lactate threshold training, this new Norwegian method of training focuses on boosting performance in the middle Zone 2 and Zone 3 effort, or “sweet spot,” propelling these athletes to jaw-dropping performances.

In his ground-breaking The Norwegian Method book, sports journalist Brad Culp unpacks the rise of this new method and its meticulous scientific protocols, which upend long-held beliefs about training and performance.

Culp discovers that the secrets to Norwegian endurance dominance aren’t just in their training method. With its rugged terrain and harsh weather, Norway has a way of hardening competitors for any test. Culp explores the how the Scandinavian culture imbues a unique biopsychosocial approach to performance. He also introduces the athletes, coaches, and scientists who are shaking up the world of endurance sports. Their secret? Plenty of volume at low intensity, punctuated with hard-fought double-threshold workouts, which seems to turn workhorses into winners—they know when to hold back and when to go all-out.

The Norwegian Method is a real-life story of how discipline and determination can be employed to overcome seemingly impossible odds and achieve breakthrough performances. Culp gives endurance athletes a blueprint of how to adapt their training to look more like that of Norway’s Jakob Ingebrigtsen and Kristian Blummenfelt.