Anthony (Tony) Okely is a Senior Professor and Director of Research at Early Start at the University of Wollongong, Australia. Tony’s research focuses on physical activity and sedentary behaviour in children. Tony led the research team that developed and recently updated the Australian 24-hr Movement Guidelines for Children 0-5 years, and the Australian 24-hr Movement Guidelines for Children and Young People. He was also part of the Guideline Development Group for the WHO guidelines on physical activity, sedentary and sleep behaviours in children under 5 years of age, South African 24-hr Movement Guidelines for Birth to 5 Years, and UK Physical Activity Guidelines for children under 5. He is current leading an international surveillance study of 24-hour movement behaviours in the early years (called SUNRISE) which will involve around 30 countries, more than half of which are either low- or middle-income according to the UN Human Development Index.