Physical inactivity in adolescents (Indicator 6)

This indicator is part of Target (3): A 10 per cent reduction in insufficient physical activity.

The indicator is based on physical activity among children and adolescents, measured using an accelerometer. It describes the proportion of insufficiently physically active children and adolescents, defined as failing to meet national recommendations for physical activity.

Approximately 10-30 per cent of nine-year-olds and approximately 50 per cent of 15-year-olds were insufficiently physically active according to measurements taken with accelerometers in 2005/06, 2011/12 and 2018. Data are from the Physical Activity among Norwegian Children Study (PANCS).

There was no definitive change over time in the proportion of nine and 15-year-olds who did not meet the recommendations for physical activity between 2005/06, 2011/12 and 2018. 

The proportion of physically inactive children was higher among girls than among boys in both groups, and higher among 15-year-olds than among nine-year-olds.  

Figure 1: The proportion (%) not meeting the physical activity recommendations by accelerometry among nine and 15-year-olds in 2005/06, in 2011/12 and in 2018. Source: Physical Activity among Norwegian Children Study (PANCS), the Norwegian School of Sport Sciences, the Norwegian Directorate of Health and the Norwegian Institute of Public Health.

Data sources

The data source for this indicator is the Physical Activity among Norwegian Children Study (PANCS).

A description of PANCS follows below.

Description 

Accelerometer data on physical activity were obtained from PANCS1, PANCS2 and PANCS3 UngKan2. In 2005/06 (PANCS1), nationally representative samples of nine-  (n=1470) and 15-year-olds (n=1348) were invited to participate. Of these, 1306 (88.8 per cent) and 993 (73.7 per cent) consented to participate, respectively. 1127 nine-year-olds and 702 fifteen-year-olds contributed sufficient accelerometer data to be included in the analyses. 

The second wave of the survey was in 2011/2012. In PANCS2, 1945 nine-year-olds and 1759 fifteen-year-olds were invited to participate. Of these, 1421 nine-year-olds (73 per cent) and 1106 fifteen-year-olds (63 per cent) agreed to participate, from which 1305 and 972 nine- and fifteen-year-olds contributed sufficient accelerometer data to be included in the analyses, respectively. 

The third wave of the survey was conducted in 2018 (PANCS3). In PANCS 3, 1846 and 2314 nine and fifteen-year olds were invited. Of these, 1343 nine-year-olds (73 per cent) and 1325 fifteen-year-olds (57 per cent) agreed to participate. 1219 and 989 nine- and fifteen-year olds contributed sufficient accelerometer data to be included in the analyses, respectively.  

Data on the proportion not meeting the recommendations among children and adolescents are based on the reports from the three waves of PANCS:

• PANCS1: Physical activity among children and adolescents – Results of a survey of nine- and 15-year-olds in 2005-2006. Report by the Norwegian Directorate of Health, 2008, ISBN-978-82-8081-101-1
• PANCS2: Physical activity among six-, nine- and 15-year-olds in Norway - Results of a survey in 2011. Report by the Norwegian Directorate of Health, 2012, ISBN no. 978-82-8081-262-9
• PANCS3: Physical activity among six-, nine- and 15-year-olds in Norway - Results of a study in 2018. Report by the Norwegian Institute of Public Health. Oslo 2019.   

In addition, the data are based on a paper describing the activity levels in the PANCS studies by Dalene et al. and by Stene-Joannessen et al  

References: 

• Dalene KE, Secular and longitudinal physical activity changes in population-based samples of children and adolescents. Scand J Med Sci Sports 2017 (http://onlinelibrary.wiley.com/doi/10.1111/sms.12876/full%22%20/t%20%22_blank) .  
• Stene-Joannessen J, Temporal trends in physical activity levels across more than a decade – a national physical activity surveillance system among Norwegian children and adolescents. Int J Behav Nutr Phys Act, 2021. 

Effect measure

• The proportion (%) of children not meeting the physical activity recommendations based on device-measured physical activity using accelerometry, among nine-year-olds. 

• The proportion (%) of adolescents not meeting the physical activity recommendations based on device-measured physical activity using accelerometry, among 15-year-olds.  

Based on the accelerometer data, all participants who accumulated an average of fewer than 60 minutes of moderate to vigorous physical activity per day were defined as not meeting the recommendations for physical activity. The average was calculated by dividing the number of minutes of moderate to vigorous physical activity recorded over the measurement period by the number of days the accelerometer was worn. Only data from days on which the accelerometer was worn for eight hours or more were included.   

Interpretation and sources of error

Accelerometry is a reliable and valid method that provides reasonable estimates on the prevalence of physical activity among children and adolescents at group level. Accelerometers have certain weaknesses. They provide imprecise measurements of certain activities (e.g. cycling), which in some cases may produce less accurate data at the individual level. Further, it may be argued that using the average number of minutes of moderate to vigorous physical activity per day in the PANCS studies is somewhat liberal, although in agreement with the most recent recommendations from the WHO.

Data quality

Data on the proportion of participants who are physically active according to the recommendations based on accelerometer data are highly accurate and should be used when examining trends over time in physical activity in children and adolescents.

WHO’s definition of the indicator

Indicator 6. Prevalence of insufficiently physically active adolescents, defined as less than 60 minutes of moderate to vigorous intensity activity daily.

National adaptation

WHO’s indicator is based on self-reporting. We present device-based measurement data from accelerometry.

WHO’s indicator applies to adolescents. We present additional data for children.