This special topic of theJournal of Sport and Health Science(JSHS) focused onPolicy and physical activitywas edited by Dr Ruopeng An. It includes 1 guest editorial, 2 review articles, and 1 original article contributed by resesarch scientists from USA, UK, Ireland, and China,etc. Below, we present the biographies of the guest editor and the main authors.

Dr Ruopeng An is an Associate Professor at Brown School, Washington University in St. Louis. Dr An conducts research to assess environmental influences and populationlevel interventions on weight-related behaviors and outcomes throughout the life course. In particular, his work assesses socioeconomic determinants and policies that impact individuals’ dietary behavior, physical activity, sedentary lifestyle; and adiposity in children, adults of all ages, and people living with a disability. Dr An’s numerous publications include articles in journals such as theAmerican Journal of Preventive Medicine,Obesity Reviews,Social Science & Medicine, andPediatric Obesity. His research has been widely featured in media, includingTime,the New York Times,Los Angeles Times, andCable News Network(CNN). In 2015, Dr An received the Judy K.Black Early Career Research Award from the American Academy of Health Behavior. In 2018, he was elected as a Fellow of the American College of Epidemiology.

Prof Catherine Woods is the Chair of Physical ActivityforHealth in the Department of Physical Education and Sport Sciences at the University of Limerick (UL). As the Director of UL’s recently established Physical ActivityforHealth Research Cluster,her research cuts across the themes of physical activity policy, promotion, and implementation. Working across the life course, Prof Woods enjoys developing and testing theoretically sound interventions to enhance physical activity, and seeks better, more systematic methods of bringing research, practice, and policy closer together to achieve real and sustainable impact. Prof Woods believes that physical activity is a best buy for public health as it has the potential to improve health and well-being for everyone, irrespective of age, ability, or condition.

Dr Anna Chalkley is a Senior Research Associate at the School of Sport, Exercise and Health Sciences at Loughborough University. Dr Chalkley’s research has focused on the development, implementation, and evaluation of interventions to promote physical activity in children and young people. She is particularly interested in the translation of research and how it is used to inform policy and practice, as well as exploring how interventions can be effectively implemented in the real world and scaled. Dr Chalkley is a board member of the International Society for Physical Activity and Health and is also a member of the steering committee for the European Network for Health Enhancing Physical Activity (HEPA Europe) and co-chairs the Working Group for Children and Adolescence.