In this episode of She Leads Science, Liz Joy sits down with Janet E. Fulton, PhD, an epidemiologist and former Chief of the Physical Activity and Health Branch at CDC, whose work has quietly shaped how the U.S. measures, understands, and promotes physical activity. Together they unpack Janet’s path and leadership in federal public health, what “surveillance” really means (and why it isn’t as scary as it sounds), and how data on steps, sedentary time, and walkable communities can actually move mayors, health systems, and school boards to act. They also talk candidly about disruption at CDC, the future public health workforce, and what it really takes to lead science with integrity in a time of mistrust.