In May 2014, representatives from 15 countries gathered in Toronto, Canada, for the Global Summit on Physical Activity of Children. Experts reviewed available information and assigned a grade for 9 indicators in national Physical Activity Report Cards. Australia received a grade of “D minus(–)” for sedentary behaviors, with only 29% of 5- to 17-year-olds meeting screen time recommendations. A smaller group from the Australian Report Card Research Working group conducted a study to further review available evidence about sedentary behaviour in children (available here).
They asked the following 3 questions:
Question 1: What are the main sedentary behaviors of children?
Sedentary behavior can occur in 4 areas of children’s lives—education/school/child care, transport, self-care/domestic chores, and leisure/play. For school-aged children, a main “occupation” is being a student and the majority of the school day is spent sitting. Homework also contributes to additional sitting time. Transport time is usually highly sedentary with children sitting in buses, trains and cars to get to and from school and other destinations. Sedentary self-care tasks include eating and some grooming. Leisure and play sedentary behaviors include reading from a book or an electronic screen. Sedentary behaviors are often further classified as being either based around an electronic screen or not.
Question 2: What are the potential mechanisms for sedentary behaviors to impact child health and development?
There are a number of ways by which sedentary behaviors may influence child health and development, including disrupted metabolism, limited neuromuscular activity, prolonged/awkward postures or repetitive motions, socioemotional experiences, cognitive experiences, and other mechanisms such as influencing sleep quality.
Question 3: What are the effects of different types of sedentary behaviors on child health and development?
Research suggests that sedentary behaviors impact child health and development including cardiometabolic, neuromuscular, and psychosocial implications. However, most of the research is about the effects of watching TV, and there has been less of a focus on the effects of total screen time, screens other than TV, non-screen sedentary behaviours, and total sedentary time.
The available research, while incomplete, is sufficiently convincing that sedentary behaviors are important for child health and development. Nations therefore need to balance children’s healthy and unhealthy sedentary behaivours in order to improve their sedentary behaviour grade in future report cards.
Leon Straker, Erin Kaye Howie, Dylan Paul Cliff, Melanie T. Davern, Lina Engelen, Sjaan R. Gomersall, Jenny Ziviani, Natasha K. Schranz, Tim Olds, Grant Ryan Tomkinson. Australia and Other Nations Are Failing to Meet Sedentary Behaviour Guidelines for Children: Implications and a Way Forward. JPAH 13:177 – 188, 2016.