Professor Stephen Seiler is a world-leading exercise physiologist noted for his transformative research on endurance training and intensity distribution. With roots in the US, he has spent over two decades in Norway, where he formerly served as Vice-Rector for Research and Innovation and Dean of the Faculty of Health and Sport Sciences at the University of Agder. Currently, he continues there as Professor of Sports Science.

Over the past 15 years, Prof. Seiler has earned international recognition through both descriptive and experimental research on endurance athletes—cyclists, rowers, cross-country skiers, orienteers, and distance runners—advancing the understanding of training intensity distribution and polarised training models. His work catalysed widespread adoption of the 80/20 training paradigm, an evidence-based structure proven effective in both elite and recreational athletes, and has inspired a global shift in performance programming.

He has published over 100 peer‑reviewed articles, authored more than 100 popular science articles, and frequently lectures at scientific events across Europe, North America, China, South Africa, and Australia. He also helped establish the Elite Sport Performance Special Interest Group on the executive board of the European College of Sport Science (2014–2019), and is a founding editorial board member of the International Journal of Sport Physiology and Performance. Prof. Seiler’s enduring legacy is his ability to integrate rigorous science with real-world coaching practice.