On November 12, 2022, we got the sad news that Professor Louis Passfield had passed way. Our thoughts are now with Louis’s family and friends. He was a remarkable and respected man, an inspiration as a person, leader, scientist, and sport practitioner. His passion for physiology and performance in sports, in particular cycling, was tremendous. In his last YouTube video, posted not long before he passed away, Louis was riding his bike and talking passionately about his own training, generously sharing his wisdom of sport physiology and performance.

Louis was professor and head of school at the University of Kent and had a long-lasting career as a sport scientist with British Cycling. He was a role model for the mission of IJSPP: “to advance the knowledge of sport and exercise physiologists, sport scientists, sport physicians, and sport-performance researchers.” He served on our editorial board and published 7 of his last 10 papers in our journal. Not only did he publish high-quality research that led to important discussions in the scientific society, but he also had a major impact on sport practice. He respectfully challenged current perspectives—never with the aim of winning the discussion, always with the goal of understanding more.

To highlight some of the key points that we should all learn from Louis, we have asked some of his closest friends and colleagues to share their experiences.

I (G.B.) was fortunate enough to spend my formative PhD student years at the University of Brighton with Louis. Louis was my hero—he was bright, sharp witted, and never failed to be interested in others or curious about the world of exercise physiology. He would always be laughing and playing pranks. In the early days of email, he managed to hack into the head of school’s email to send me a Valentine’s message from the head of school. He was an innovator, and I loved attending conferences with him, where he could ask curious questions and hang out with the real legends of our field. We ran marathons and ultramarathons together, just laughing at each other through the pain barrier. His knowledge and sharing of ideas on endurance physiology and cycling enabled so many of us to enter a new era of sporting success. His early work was on glycogen depletion, and in the applied world he was one of the pioneers of heat and altitude training. Deep down he cared about his work colleagues and students and was able to inspire thousands in our field. Always smiling, always sharing ideas, always trying things out on himself before passing them on to athletes and coaches.

I (M.B.) first met Louis in 1996 when I was an undergraduate at the University of Brighton. He made an immediate positive impression for a number of reasons. He taught training theory with boundless enthusiasm, which is one of the key experiences that that led me to a career in sport and exercise science. His humor was on display from the beginning; he introduced himself by saying that he was part of a support team in Atlanta whose charges (the men’s pursuit team) came in fourth. He gestured to the door and said, “So if you want to leave now, I totally understand!” He was the first lecturer to really show me how far enthusiasm, close logic, and careful methods can take you. It’s a lesson I’ve never forgotten. He was present in the first week of my PhD studies, as he was just finishing his. I was lucky to spend a few hours in a pub in the company of Louis and Ron Maughan (his external examiner). Louis must have done a good job with his work, as he soon found employment with Ron in Aberdeen. We crossed paths frequently thereafter, especially when we both worked in different parts of Wales. Conversations were always scientifically stimulating and often filled with laughter. Louis and I shared a train ride back from a conference in Glasgow in 2010, where he mentioned that he was setting up an endurance research group at the University of Kent. Little did I know that he had planted a seed that led me to Kent 2 years later, with Louis as my boss.

We (S.M., J.H., and A.P.) met Louis when he came to the University of Kent following several years at British Cycling working with their high-performance athletes at the pinnacle of what we now see as one of their most successful periods. He could have arrived and told us all how great he was and what he was going to do to revolutionize sport science at Kent, but he did not. He was humble, generous with his time, and supportive to all colleagues. He joined the department at a time when most of the staff were in the early stages of their careers. He was a mentor to many and continued to be for all the time he was at Kent. As a scientist, he focused his work mostly on the determinants of cycling performance and how to improve them through training. From an applied perspective, he never forgot that there needed to be an outcome from his research that improved or informed practice of athletes, coaches, or other scientists. Louis valued interdisciplinary and multidisciplinary research that integrated physiology with other sciences. This approach is exemplified by the development of the Endurance Research Group in Kent. His soft-spoken nature and ability to communicate even the most complex concepts in a simple and easy-to-understand manner meant that he could bridge the gap between life in academia and the applied world of high-performance sport.

This memorial reflects our admiration of a unique person and scientist, a role model for all of us. We’ll miss you dearly.