Dr Fiona Bull is head of the Physical Activity Unit in the Department of Health Promotion at the World Health Organization at the Headquarters in Geneva, Switzerland. Dr Bull leads the technical work providing global policy and resources for the promotion of physical activity. She led the development of the Global Action Plan on Physical Activity 2018-2030: More active people for a healthier world, the update of Global guidelines on physical activity and sedentary behaviour in 2022, and the 1st Global Status Report on Physical Activity in November 2022. Most recently she co-authored the updating of the 2018 global comparable estimates of physical inactivity in adults launched in June 2024. Dr Bull and her team support countries to increase participation in physical activity through active transport, sport and every-day activities through advancing science, policy and practice. Prior to WHO, Dr Bull was Professor of Physical Activity and worked in academic and research in Australia and the U.K. and at the Centers for Disease Control (CDC) in the USA.