BACKGROUND: Studies of correlates of active transport to and from school (ATS) focus mainly on children, have a limited conceptualisation of ATS trips, lack heterogeneity in built environments, and rarely consider effect modifiers. This study aimed to estimate associations of parent-perceived neighbourhood environment characteristics with self-reported ATS among adolescents from 14 countries, and whether associations differ by sex, city/region, and distance to school. METHODS: Observational cross-sectional design. Data were from the International Physical activity and Environment Network (IPEN) Adolescent study and included 6302 adolescents (mean age 14.5 ± 1.7 years, 54% girls) and a caretaker from 16 diverse sites. Adolescents self-reported usual travel to and from school by walking and bicycling (days/week) and time it would take to walk. Parents completed the Neighbourhood Environment Walkability Scale for Youth (13 scores computed). Generalised additive mixed models estimated associations of parent neighbourhood perceptions with 1) any active transport to/from school, 2) regular walking (5-10 times/week), 3) regular cycling to/from school, and 4) profiles of ATS generated using latent profile analyses. Interactions were also explored. RESULTS: Overall, 58.7% reported any ATS, 39.9% regularly walked, 7.7% regularly cycled, and four profiles of ATS were identified: walk to and from school; walk from school; cycle to and from school; no ATS. Distance to school was negatively associated with all outcomes, though evidence was weak for regular cycling to/from school. Land use mix - diversity was positively related to all ATS outcomes except those related to cycling. Accessibility and walking facilities were associated with higher odds of any ATS, regular walking to/from school, and the profile walking to and from school. Residential density was negatively related to regular cycling to/from school. Positive associations were observed between traffic safety and any ATS, and between safety from crime, aesthetics, and odds of regular cycling to/from school. Distance to school, adolescent sex, and city moderated several associations. CONCLUSIONS: Parent perceptions of compact, mixed-use development, walking facilities, and both traffic and crime-related safety were important supportive correlates of a range of ATS outcomes among adolescents in high- and low-middle-income countries. Policies that achieve these attributes should be prioritised to support more widespread ATS.

• Klíčová slova
• Active transport, Correlates, Cycling, International, Perceived environment, Physical activity, School travel, Walkability, Walking, Youth,
• MeSH
• charakteristiky bydlení * MeSH
• charakteristiky okolí bydliště * MeSH
• chůze * MeSH
• cvičení * MeSH
• cyklistika MeSH
• doprava * MeSH
• lidé MeSH
• mladiství MeSH
• percepce MeSH
• průřezové studie MeSH
• rodiče * psychologie   MeSH
• školy * MeSH
• vytvořené prostředí MeSH
• životní prostředí - projekt * MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH

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.

• Klíčová slova
• Accelerometer, Built environment, Screen time, Sedentary time, Social media, Youth,
• MeSH
• akcelerometrie MeSH
• čas strávený před obrazovkou MeSH
• charakteristiky bydlení * MeSH
• chování mladistvých MeSH
• cvičení MeSH
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• průřezové studie MeSH
• průzkumy a dotazníky MeSH
• rodiče MeSH
• sedavý životní styl * MeSH
• sociální média MeSH
• životní prostředí - projekt MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• pozorovací studie MeSH

OBJECTIVES: The aim of this study was to developed sex- and age-specific normative-referenced percentile values for health-related fitness among 12 to 18 years old Czech youth. METHODS: This study included cross-sectional data from 1,173 participants (50.7% boys) collected between 2013 and 2016. Participants were recruited from 32 elementary or secondary schools across eight cities located in the Czech Republic. Health-related fitness was objectively measured using both anthropometric (height, body mass, and sum of skinfolds) and performance (20-m shuttle run for cardiorespiratory endurance, modified push-ups for muscular strength/endurance, and V sit-and-reach for flexibility) tests. Sex- and age-specific normative values were calculated using the Lambda Mu Sigma method. Sex- and age-related differences in means were expressed as standardized effect sizes. RESULTS: Normative percentiles were tabulated and displayed as smoothed curves. Among boys, measures of health-related fitness generally increased with age, except for an age-related decline in the sum of skinfolds and a plateau in V sit-and-reach. Among girls, most measures of health-related fitness increased from age 12 to 16 years before stabilizing, except for the sum of skinfolds, which remained stable from age 12 to 18 years. The sex-related differences were large with boys having higher cardiorespiratory endurance and muscular strength/endurance than girls. Girls compared to boys had higher flexibility. CONCLUSIONS: This study presents the most up-to-date sex- and age-specific normative-referenced percentile values for health-related fitness among Czech youth. Normative values may be useful for fitness and public health screening and surveillance, for example, by helping to identify youth with low fitness who might benefit from a fitness-enhancing intervention.

• Klíčová slova
• anthropometry, normative data, percentiles, performance, physical fitness, youth,
• MeSH
• cvičení MeSH
• dítě MeSH
• index tělesné hmotnosti MeSH
• lidé MeSH
• mladiství MeSH
• průřezové studie MeSH
• tělesná výkonnost * MeSH
• zátěžový test * MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND: This study examined the strength, shape and direction of associations of accelerometer-assessed overall, school- and non-school-based moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with BMI among adolescents across the world. Second, we examined whether these associations differed by study site and sex. METHODS: Cross-sectional data from the IPEN Adolescent study, an observational multi-country study, were used. Participants wore an accelerometer for seven days, reported height and weight, and completed a socio-demographic survey. In total, 4852 adolescents (46.6% boys), aged 11-19 years (mean age = 14.6, SD = 1.7 years) were included in the analyses, using generalized additive mixed models. RESULTS: Adolescents accumulated on average 41.3 (SD = 22.6) min/day of MVPA and 531.8 (SD = 81.1) min/day of ST, and the prevalence of overweight and obesity was 17.2% (IOTF), but these mean values differed by country. Linear negative associations of accelerometer-based MVPA and ST with standardized BMI scores and the likelihood of being overweight/obese were found. School-based ST and non-school-based MVPA were more strongly negatively associated to the outcomes than non-school based ST and school-based MVPA. Study site moderated the associations; adolescent sex did not. No curvilinear associations were found. CONCLUSIONS: This multi-country study confirmed the importance of MVPA as a potential protective factor against overweight/obesity in adolescents. Non-school-based MVPA seemed to be the main driver of these associations. Unexpected results were found for ST, calling for further examination in methodologically sound international studies but using inclinometers or pressure sensors to provide more precise ST measures.

• Klíčová slova
• Adolescents, Body weight, Exercise, Physical activity, Public health,
• MeSH
• akcelerometrie MeSH
• cvičení MeSH
• index tělesné hmotnosti MeSH
• lidé MeSH
• mladiství MeSH
• nadváha * epidemiologie   prevence a kontrola   MeSH
• obezita epidemiologie   prevence a kontrola   MeSH
• průřezové studie MeSH
• sedavý životní styl * MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH