Body image, body composition and environment:do they affect adolescents' physical activity?

BACKGROUND: Most adolescents are less physically active than recommended, despite the strong effort of various stakeholders to promote physical activity (PA). Body image and body composition may play an important role not only in directly facilitating adolescents' PA but also in enabling environment-related factors. As evidence is lacking, we aimed to assess the associations of adolescents' PA with body-related and environment-related factors, whether this differs by age and gender, and whether these factors interact. METHODS: We used data on 888 11- to 15-year-old adolescents (mean age = 13.5, 56% boys) from the Health Behaviour in School-aged Children study conducted in 2018 in Slovakia. We used multinomial logistic regression analysis to assess the association of adolescents' PA with body-related factors (body image, body composition) and environment-related factors (PA-promoting environment, less leisure constraints), taking into account age and gender. RESULTS: Adolescents who perceived their body as not too fat were more likely to be physically very active rather than inactive [odds ratios (ORs)/95% confidence interval (CI) 2.15/1.44-3.22], and similarly those who were not overweight/obese (3.24/2.09-5.01) and perceived less leisure constraints (1.74/1.44-2.11). In older adolescents and in girls, the association of adolescents' PA with body composition and environment-related factors was stronger. The association of adolescents' PA with perceiving less leisure constraints was stronger among adolescents who did not perceive their body as too fat (OR/95% CI 1.98/1.26-3.14), and for those who were not overweight/obese (OR/95% CI 1.62/1.01-2.57). CONCLUSION: Adolescents' PA is associated with both body-related and environment-related factors. These associations are stronger in girls and older adolescents, if co-occurring

Test-Retest Reliability of a Questionnaire on Motives for Physical Activity among Adolescents

The aim of this study was to investigate the test-retest reliability of the motives for undertaking physical activity (PA) items from the Health Behavior in School-Aged Children (HBSC) study questionnaire among Slovak and Czech adolescents and to determine whether this reliability differs by gender, age group and country. We obtained data from 580 students aged 11 and 15 years old (51.2% boys) who participated in a test and retest study with a four-week interval in 2013 via the Health Behavior in School-Aged Children cross-sectional study in the Czech Republic and Slovakia. We estimated the test-retest reliability of all 13 dichotomized motives by using Intraclass Correlation Coefficients (ICC) and Cohen's Kappa statistics, for continuous and dichotomized motives, respectively. Test-retest reliability showed moderate agreement for nine motives (ICC from 0.41 to 0.60) and fair agreement for four motives (ICC from 0.33 to 0.40). Kappa statistics were similarly moderate to large (0.33 to 0.61), except for three motives with small or trivial correlations. The motives "To improve my health" and "To enjoy the feeling of using my body" had consistently low Kappas and correlations. Overall, the results of this study suggest that most questions on motives for PA on the HBSC questionnaire have acceptable test-retest characteristics for use among adolescents

Is BMI a Valid Indicator of Overweight and Obesity for Adolescents?

Background: Overweight and obesity are mostly monitored via the Body Mass Index (BMI), based on self-reported or measured height and weight. Previous studies have shown that BMI as a measure of obesity can introduce important misclassification problems. The aim of this study was to assess the validity of overweight and obesity classification based on self-reported and on measured height and weight versus the proportion of body fat as the criterion. Methods: We used data on 782 adolescents (mean age = 13.5, 55.8% boys) from the Health Behaviour in School-Aged Children (HBSC) study conducted in 2018 in Slovakia. We obtained self-reported (height and weight) and objective measures (height, weight) and the proportion of fat (as the criterion measure) measured via bioimpedance body composition analysis (BIA) with an InBody 230 from the adolescents. Results: Both measured and self-reported BMI indicated overweight and obesity with relatively low sensitivity (66-82%), but high specificity (90-92%). The superior accuracy of measured BMI in comparison to self-reported BMI was confirmed by the area under the curve (AUC) based on the receiver operating characteristics (ROC) curves (AUC measured/self-reported: 0.94/0.89; p < 0.001). The misclassification of overweight and obesity was significantly higher when using self-reported BMI than when using measured BMI. Conclusion: Both self-reported and measured BMI as indicators of overweight and obesity underestimate the prevalence of adolescents with overweight and obesity

Do Motives to Undertake Physical Activity Relate to Physical Activity in Adolescent Boys and Girls?

Low levels of physical activity (PA) during adolescence contribute to obesity and poor health outcomes in adolescence, and these associations endure into adulthood. The aim of this study was to assess the associations between motives for PA and the level of PA among adolescent boys and girls. We obtained data regarding motives for PA and frequency of PA in 2010 via the Health Behavior in School-aged Children cross-sectional study in the Czech and Slovak Republics (n = 9018, mean age = 13.6, 49% boys). Respondents answered questions about their motives for PA and the frequency of their PA. Motives for PA were assessed using 13 items, which were structured in four groups. We explored the association between the motives for PA and sufficient PA using univariate and multivariate logistic regression models adjusted for age, and separately for boys and girls. “Good child” motives and Achievement motives were significantly associated with sufficient PA among both boys and girls. Health motives were associated with sufficient PA only among boys, and Social motives were associated with sufficient PA only among girls. Motives for PA were associated with the level of PA, and this association was partially gender dependent. These gender differences should be considered in interventions focusing on enhancement of PA

Associations between perceived social and physical environmental variables and physical activity and screen time among adolescents in four European countries

The study was supported from European Regional Development Fund-Project “Effective Use of Social Research Studies for Practice” (No. CZ.02.1.01/0.0/0.0/16_025/0007294) and the Czech Science Foundation under reg. No. 18-24977S.Objectives: Associations between the perceived social and physical environment and self-reported moderate-to-vigorous physical activity (MVPA) and screen time (ST) were examined among adolescents in four European countries. Methods: Representative samples were surveyed with standardised methodologies. Associations between environmental variables and meeting MVPA recommendations and tertiles of ST were tested in gender-specific logistic regression models. Moderation by country and country-specific relationships were also examined. Results: The most consistent findings across countries were found for the significant associations between neighbourhood social environment and MVPA in both boys and girls. Significant associations with the physical environment varied more between countries and by gender. The most consistent negative associations with ST were found for the social environmental variable of having parental rules for spending time outside the home. Conclusions: The present findings provided evidence for the generalisability of the associations between environmental correlates and MVPA across four European countries. The findings show clear differences in correlates for MVPA and ST. Further research is needed to better understand the unique aspects of the social and physical environment which explain each of the two behaviours.PostprintPeer reviewe

Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries (n = 13,800, mean age = 14.4, 49.4% boys). We explored the association of perceived environment (e.g., “There are other children nearby home to go out and play with”) with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR) for one standard deviation (SD) change = 1.11, 95% confidence interval (CI) 1.05–1.18) and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88–0.98). Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence

Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity—GoPA! 2015 and 2020 Surveys

Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion

Are school factors and urbanization supportive for being physically active and engaging in less screen-based activities?

The aim was to assess the association between physical activity and screen-based activities in adolescents and selected school factors and urbanization and whether these associations were modified by degree of urbanization.We obtained data regarding the fifth-ninth grade students from 130 schools in 2014 via the Health Behaviour in School-aged Children cross-sectional study in Slovakia (n = 9743, mean age = 13.5, 50.3% boys). We explored the associations using multilevel logistic regression.We found significant associations between physical activity and the accessibility of an area for skating/tennis court [odds ratio (OR) = 1.20 and 95% confidence interval (CI) 1.01-1.42], and between physical activity and active breaks (OR = 0.83 and 95% CI 0.69-0.99). The rates of screen-based activities were higher in small towns (OR = 1.63, 95% CI 1.29-2.06), towns (OR = 1.30, 95% CI 1.08-1.57), and cities (OR = 1.40, 95% CI 1.04-1.87) than in villages.School environment and degree of urbanization are associated with adolescents' physical activity and screen-based activities. This holds positively for access to an area for skating/tennis court and negatively for active breaks regarding physical activity and for living in villages regarding less use of screens.</p

Does it fit better? Measures of physical activity among adolescents in relation to health indicators

BACKGROUND: Measuring physical activity (PA) is one of the pillars of successful health promotion; however, we struggle to find a tool enabling the identification of risk groups. The current standard approach of assessing moderate-to-vigorous physical activity (MVPA) every day does this inadequately. The aim of this study is to explore whether three other indicators of adolescents' PA can identify such risk groups in a better way. METHODS: We used data on 888 11- to 15-year-old adolescents (mean age = 13.5, 56% boys) from the Health Behaviour in School-aged Children study conducted in 2018 in Slovakia. Sufficient PA was indicated by the following four indicators: (i) MVPA every day, (ii) MVPA 5-7 days a week, (iii) engagement in organized sports (team or individual) and (iv) combining MVPA 5-7 days a week and engagement in organized sports. We used binary logistic regression analysis to assess the association of various indicators of adolescents' PA with body composition, cardiovascular fitness and self-rated health (SRH), considering age and gender. RESULTS: Being active based on various indicators was associated with better health outcomes, with the strongest associations for the indicator combining MVPA 5-7 days a week and engagement in organized sports. The only exceptions were the non-significant associations of active adolescents (being active 5-7 days per week or engaged in organized sports) with cardiovascular fitness and SRH. CONCLUSIONS: Measuring PA using an indicator that combines MVPA 5-7 days a week and engagement in organized sports is the most valid using three health indicators as criteria