Sedentary behaviour is characterised as any waking behaviour whereby energy expenditure ≤1.5 metabolic equivalents (METs), while in a sitting, reclining, or lying posture. Sedentary behaviour is related to poor health outcomes among children and adolescents, such as poorer cardiometabolic health and fitness, increased adiposity, poorer behavioural conduct/pro-social behaviour, and reduced sleep duration. An emerging evidence base also suggests sedentary behaviour is associated with well- being and quality of life. Children and young people typically spend a large proportion of their day engaging in sedentary pursuits, such as sitting down whilst at school (e.g. during lessons or break time), non-active travel (e.g. bus or car), and sitting during leisure time (e.g. watching television or playing video games). It is currently unknown whether a dose-response relationship exists between sedentary behaviour and health outcomes among young people. That said, the World Health Organization (WHO) notes that adverse health effects of sedentary behaviour are generally stronger for television viewing or recreational screen time than for total sedentary time. Earlier studies observed a reduction in physical and psychosocial health outcomes amongst young people who spend less than two hours engaging in sedentary behaviours.
The benchmark used by the Research Working Group to allocate a grade to this indicator was ‘the percentage of young people who exceed the recommended sedentary time guidelines (i.e. two or more hours)’. Data on sedentary behaviours, such as time spent sitting during free time on weekdays or screen time, were used.
- The HAPPEN survey (2018-2020), children aged 8 to 11 years (n=1,329)
- The School Health Research Network’s Student Health and Wellbeing survey (2019/2020), children aged 11 to 16 years (n=115,944)
Deciding on a grade
The School Health Research Network: Student Health and Wellbeing Survey (2019) collated self-report sedentary data on 110,877 children aged 11 to 16 years old. Distributed to 198 schools in Wales, young people were asked how much time spent sitting they had undertaken outside of school hours during free time on weekdays.
The survey showed that 86.4% of young people spent two or more hours sitting during weekdays. Reports were found to be higher among boys (87.2%) compared to girls (85.7%). When drawing comparisons across age groups, there was a clear gradient, with the lowest ‘two or more hour’ reports among Year 7 pupils (76.7%) and the highest reports among Year 11 pupils (92.2%). No clear patterning in ‘two or more hours’ reports were found when comparing across socioeconomic (low 86%, medium 87.5% and high 86.2%) or ethnic (White 86.7% vs Black, Asian and minority ethnic 86.1%) groupings.
The HAPPEN survey collected self-report data on 1,329 children aged 8-11 years old. The survey was distributed among 27 primary schools across three local authorities in Wales. Children were asked ‘In the last 7 days, how many days did you watch TV/play online games/use the internet etc. for 2 or more hours a day (in total)?’.
The survey showed that 32% of children reported watching TV/screens for two hours or more every day of the week. The proportions reported between boys and girls were different (34% boys and 31% girls). Across the school year groups, the highest reports of daily screen time were found among children in Year 5 (aged 9-10 years; 36%) compared to Year 4 (33%) and Year 6 (29%) peers. Socioeconomic data showed a difference in proportions, with 37% and 21% of the most deprived and most affluent children, respectively, reporting two or more hours of screen time daily.
The Research Working Group assigned an F to this category when taking the sample characteristics into account (i.e. sample representation and self-reporting). This grade has not changed from the 2018 AHK-Wales Report Card. It is important to note that the questions used for the 2018 sedentary indicator differ, with the 2018 questions also capturing sedentary behaviours on weekends. The current grade also incorporates a new dataset, with HAPPEN data availability for 2020.
Both the School Health Research Network: Student Health and Wellbeing Survey and the HAPPEN survey used self-report methods to obtain data on sedentary behaviour. There are no large-scale studies using device-based assessments of sedentary behaviour, for example, with the use of accelerometers, in the United Kingdom. Beyond the HAPPEN survey, there is currently limited research available in Wales for children under the age of 11 years. This gap needs to be addressed through robust, systematic, data collection methods. Greater attention needs to be given to socioeconomic patterning, exploring sedentary periods on a continuum and by behaviour. The effect of interventions to reduce time spent sitting needs to be quantified.
How to improve
The best available evidence shows that the majority of children and young people in Wales need to reduce their time spent sedentary. A significant effort needs to be made to address the very high amount of time spent in sedentary pursuits among young people in Wales. To inform the design of effective strategies, there is a need to first generate high-quality evidence using device-based measures, while simultaneously capturing information on the duration (e.g. per day, per week), context (e.g. school time, leisure time) and type (e.g. sitting using the phone, watching television) of sedentary behaviours.