Email updates

Keep up to date with the latest news and content from IJBNPA and BioMed Central.

Open Access Research

Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study

Tim S Olds1, Carol A Maher1*, Kate Ridley2 and Daniella M Kittel3

Author Affiliations

1 Health and Use of Time (HUT) Group, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, 5001, South Australia, Australia

2 School of Education, Flinders University, GPO Box 2100, Adelaide, 5001, South Australia, Australia

3 School of Health Sciences, University of South Australia, GPO Box 2471, Adelaide, 5001, South Australia, Australia

For all author emails, please log on.

International Journal of Behavioral Nutrition and Physical Activity 2010, 7:92  doi:10.1186/1479-5868-7-92

Published: 31 December 2010

Abstract

Background

Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST). This study aimed to (1) describe the magnitude and composition of screen sedentary time (SST) and NSST in Australian adolescents, (2) describe the socio-demographic correlates of SST and NSST, and (3) determine whether screen time is an adequate surrogate for total sedentary behaviour in this population.

Methods

2200 9-16 year old Australians provided detailed use of time data for four days. Non-screen sedentary time (NSST) included time spent participating in activities expected to elicit <3 METs whilst seated or lying down (other than sleeping), excluding screen-based activities (television, playing videogames or using computers). Total sedentary time was the sum of screen time and NSST.

Results

Adolescents spent a mean (SD) of 345 (105) minutes/day in NSST, which constituted 60% of total sedentary time. School activities contributed 42% of NSST, socialising 19%, self-care (mainly eating) 16%, and passive transport 15%. Screen time and NSST showed opposite patterns in relation to key socio-demographic characteristics, including sex, age, weight status, household income, parental education and day type. Because screen time was negatively correlated with NSST (r = -0.58), and exhibited a moderate correlation (r = 0.53) with total sedentary time, screen time was only a moderately effective surrogate for total sedentary time.

Conclusions

To capture a complete picture of young people's sedentary time, studies should endeavour to measure both screen time and NSST.