In this enlightening episode of our podcast, Dr. Olli Tikkanen engages in a deep dive with the renowned Professor James F. Sallis, the newly appointed Distinguished Professor in the Department of Family Medicine and Public Health at the University of California, San Diego. Professor Sallis, also the Director of Active Living Research and an “obesity warrior” as dubbed by Time Magazine, brings to the table over 40 years of experience in the field of physical activity and behavioral medicine. The discussion kicks off with an exploration into the evolution of physical activity recommendations and the challenges faced in the past four decades. Professor Sallis shares invaluable insights into the meticulous process of developing reliable measures, from questionnaires to accelerometers guidelines, emphasizing the importance of accurate measurement in advancing scientific research. As the conversation progresses, listeners are treated to a historical perspective on the development of these me