BACKGROUND: Understanding environmental correlates of sedentary behaviour (SB) among young people is important as such data can identify approaches to limit sedentary time. This paper estimates associations of parent-reported neighbourhood and adolescent-reported home environments with SB among adolescents aged 11-19 years from 14 countries. METHODS: In the International Physical activity and the Environment Network (IPEN) Adolescent Study (an observational, cross-sectional multi-country study), adolescents wore a triaxial accelerometer for seven days that assessed sedentary time (ST). Adolescents completed survey measures of sedentary behaviour (SB) related to recreational screen time and sitting time in motor vehicles. Parents and adolescents completed surveys assessing neighbourhood and home environments. Accelerometer based ST was available in 3,982 adolescents while survey data were available for 6,302 dyads. We estimated the total and direct effects of each environmental attribute on ST and SB. Sex of the adolescent and city/country were examined as moderators. RESULTS: The average ST in adolescents from 14 countries ranged from 7.8 to 10.5 h/day. Personal social media was the only significant correlate of total ST across both sexes. With respect to self-reported SB, adolescents accumulated an average of 3.8 h of non-school screen time per day and nearly 40 min of transport-related sitting time. Screen time was associated with all home environment variables, including social media account, as well as land use mix-diversity, traffic safety, and crime safety. Transport-related sitting time was related to land use mix-diversity, recreation facilities, walking facilities, and pedestrian infrastructure, but no home environment variables. City/country and sex were significant moderators of several associations. CONCLUSIONS: Both home and neighbourhood environment features were related to ST and SB. Having social media accounts emerged as a major contributor towards sedentarism in adolescents.

• Keywords
• Accelerometer, Built environment, Screen time, Sedentary time, Social media, Youth,
• MeSH
• Accelerometry MeSH
• Screen Time MeSH
• Residence Characteristics * MeSH
• Adolescent Behavior MeSH
• Exercise MeSH
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Cross-Sectional Studies MeSH
• Surveys and Questionnaires MeSH
• Parents MeSH
• Sedentary Behavior * MeSH
• Social Media MeSH
• Environment Design MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Observational Study MeSH

INTRODUCTION: Only international studies can provide the full variability of built environments and accurately estimate effect sizes of relations between contrasting environments and health-related outcomes. The aims of the International Physical Activity and Environment Study of Adolescents (IPEN Adolescent) are to estimate the strength, shape and generalisability of associations of the community environment (geographic information systems (GIS)-based and self-reported) with physical activity and sedentary behaviour (accelerometer-measured and self-reported) and weight status (normal/overweight/obese). METHODS AND ANALYSIS: The IPEN Adolescent observational, cross-sectional, multicountry study involves recruiting adolescent participants (ages 11-19 years) and one parent/guardian from neighbourhoods selected to ensure wide variations in walkability and socioeconomic status using common protocols and measures. Fifteen geographically, economically and culturally diverse countries, from six continents, participated: Australia, Bangladesh, Belgium, Brazil, Czech Republic, Denmark, Hong Kong SAR, India, Israel, Malaysia, New Zealand, Nigeria, Portugal, Spain and USA. Countries provided survey and accelerometer data (15 countries), GIS data (11), global positioning system data (10), and pedestrian environment audit data (8). A sample of n=6950 (52.6% female; mean age=14.5, SD=1.7) adolescents provided survey data, n=4852 had 4 or more 8+ hours valid days of accelerometer data, and n=5473 had GIS measures. Physical activity and sedentary behaviour were measured by waist-worn ActiGraph accelerometers and self-reports, and body mass index was used to categorise weight status. ETHICS AND DISSEMINATION: Ethical approval was received from each study site's Institutional Review Board for their in-country studies. Informed assent by adolescents and consent by parents was obtained for all participants. No personally identifiable information was transferred to the IPEN coordinating centre for pooled datasets. Results will be communicated through standard scientific channels and findings used to advance the science of environmental correlates of physical activity, sedentary behaviour and weight status, with the ultimate goal to stimulate and guide actions to create more activity-supportive environments internationally.

• Keywords
• epidemiology, preventive medicine, public health, statistics & research methods,
• MeSH
• Residence Characteristics MeSH
• Walking * MeSH
• Exercise * MeSH
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Cross-Sectional Studies MeSH
• Built Environment * MeSH
• Environment Design MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Observational Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Geographicals
• Australia MeSH
• Bangladesh MeSH
• Belgium MeSH
• Brazil MeSH
• Czech Republic MeSH
• Hong Kong MeSH
• India MeSH
• Israel MeSH
• Malaysia MeSH
• Nigeria MeSH
• New Zealand MeSH
• Portugal MeSH
• Spain MeSH

To achieve a healthy lifestyle, adolescents must be physically active and meet physical activity (PA) guidelines. One of the most natural ways of increasing the amount of PA is active commuting (AC) to school. Recent reviews suggest that peer norms have the potential to shape PA during adolescence in particular. Thus, our primary aim was to investigate whether Czech adolescents misperceive their peers' AC behaviors and attitudes towards AC. Our dataset comprised cross-sectional data on 1586 adolescents aged 11-15 years. Basic descriptive statistics, chi-square tests, and correlation analyses were used to analyze the data. Regarding traveling to school, 68% of the Czech adolescents in this study are daily active commuters (walking, cycling, or riding a scooter or skateboard). Less than half of the respondents believed that most of their classmates were commuting to school actively almost daily. The students who believed that most of their classmates commuted to school actively had significantly higher chances of being regular active commuters themselves. The results showed that most of the Czech adolescents misperceived the AC norms of their peers. Thus, there could be potential in using a social norms approach aimed at increasing the level of AC in Czech adolescents through targeted interventions.

• Keywords
• active transport, cycling, misperceptions, school-aged children, social norms, walking,
• MeSH
• Walking MeSH
• Bicycling * MeSH
• Child MeSH
• Transportation * MeSH
• Humans MeSH
• Adolescent MeSH
• Attitude to Health MeSH
• Cross-Sectional Studies MeSH
• Schools MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH