An umbrella review of the benefits and risks associated with youths' interactions with electronic screens.

The influence of electronic screens on the health of children and adolescents and their education is not well understood. In this prospectively registered umbrella review (PROSPERO identifier CRD42017076051 ), we harmonized effects from 102 meta-analyses (2,451 primary studies; 1,937,501 participants) of screen time and outcomes. In total, 43 effects from 32 meta-analyses met our criteria for statistical certainty. Meta-analyses of associations between screen use and outcomes showed small-to-moderate effects (range: r = -0.14 to 0.33). In education, results were mixed; for example, screen use was negatively associated with literacy (r = -0.14, 95% confidence interval (CI) = -0.20 to -0.09, P ≤ 0.001, k = 38, N = 18,318), but this effect was positive when parents watched with their children (r = 0.15, 95% CI = 0.02 to 0.28, P = 0.028, k = 12, N = 6,083). In health, we found evidence for several small negative associations; for example, social media was associated with depression (r = 0.12, 95% CI = 0.05 to 0.19, P ≤ 0.001, k = 12, N = 93,740). Limitations of our review include the limited number of studies for each outcome, medium-to-high risk of bias in 95 out of 102 included meta-analyses and high heterogeneity (17 out of 22 in education and 20 out of 21 in health with I2 > 50%). We recommend that caregivers and policymakers carefully weigh the evidence for potential harms and benefits of specific types of screen use.

Physical activity and sedentary behaviour of male adolescents in Indonesia during the COVID-19 pandemic: a mixed-method case study using accelerometers, automated wearable cameras, diaries, and interviews.

Background: Previous physical activity and sedentary behaviour studies during the pandemic have largely utilized online surveys, with known limitations including recall bias. Employing both device-based and self-reported measurements may provide a more comprehensive picture of both behaviours. Physical activity and sedentary behaviour research in adolescents is still limited in low- and middle-income countries (LMICs), including Indonesia. Male adolescents had been identified as more active than females but have had a greater decrease in physical activity during the pandemic. The present study aimed to investigate the quantity, temporal patterns, contexts, and biopsychosocial factors of physical activity and sedentary behaviour during the COVID-19 pandemic in a small group of male Indonesian adolescents. Methods: Male adolescents (n = 5; 14-15 years old) from Yogyakarta wore accelerometers and automated wearable cameras for four days, and completed diaries and interviews in November 2020. Results: Participants' activity was dominated by light intensity (67% of all physical activity). Sedentary behaviour was high; accelerometer, school days: 456 ± 145 min (78 ± 10% of wear time), non-school days: 344 ± 160 min (79 ± 17% of wear time); camera, school days: 176 ± 101 min (81 ± 46% of wear time), non-school days: 210 ± 165 min (86 ± 67% of wear time). Sedentary behaviour was mainly done during school hours on school days and from late afternoon to evening on non-school days. Screen time was largely for leisure purposes and action games were most favoured. Smartphones were the most used device, mainly used in a solitary context in the bedroom. Non-screen-based sedentary behaviour was consistently low. Interviews suggested that during the pandemic, supporting factors for physical activity are: self-determination, enjoyment, parental support, and physical education; meanwhile, factors influencing screen time are: educational demands, device and internet availability, screen time opportunities, parental control, social facilitators, phone notifications, and emotional state. Conclusions: Most participants were not able to stay active during the pandemic. Using digital platforms may be beneficial to shift some screen-based sedentary behaviour to 'screen-based' or 'screen-prompted' physical activity. Supplementary Information: The online version contains supplementary material available at 10.1186/s44167-022-00014-0.

Dose-dependent associations of joint aerobic and muscle-strengthening exercise with obesity: A cross-sectional study of 280,605 adults.

BACKGROUND: Emerging epidemiological evidence suggests that compared to engaging in 1 activity mode alone, a combination of moderate-to-vigorous physical activity (MVPA: brisk walking/jogging, cycling) and muscle-strengthening exercise (MSE: push-ups/sit-ups, using weight machines) has more favorable associations with optimal weight status. However, few studies have examined the dose-dependent and joint associations of MVPA and MSE with obesity. METHODS: Based on cross-sectional analyses of the European Health Interview Survey Wave 2 (2013-2014), we examined prevalence ratios (PRs) of joint and stratified associations between MVPA (4 categories: (i) 0 min/week, (ii) 1-149 min/week, (iii) 150-299 min/week, and (iv) ≥300 min/week) and MSE (3 categories: (i) 0 day/week, (ii) 1 day/week, and (iii) ≥2 days/week) with body mass index-defined obesity (body mass index of ≥30.0 kg/m2) using Poisson regression with robust error variance. PRs were examined unadjusted and adjusted for sociodemographic and lifestyle characteristics (e.g., sex, age, education, income, and smoking status). RESULTS: Data were available for 280,456 adults (≥18 years), of which 46,166 (15.5%) were obese. The interaction MVPA × MSE guideline adherence was statistically significant for obesity (p ≤ 0.05). The joint MVPA-MSE analysis showed that compared to the reference group (i.e., no MVPA and no MSE), the PRs followed a dose-dependent pattern, with the lowest observed among those reporting ≥150 MVPA min/week and ≥1 MSE days/week (PR: 0.43; 95% confidence interval: 0.41-0.46). When stratified across each MVPA strata, the PRs were mostly lower among those engaging in MSE 1 day/week, as compared to those doing MSE ≥2 days/week. CONCLUSION: There was evidence for a dose-dependent association between joint MVPA-MSE with a reduced prevalence of obesity. Public health strategies for the prevention and management of obesity should recommend both MVPA and MSE.

Where Does the Time Go? Displacement of Device-Measured Sedentary Time in Effective Sedentary Behaviour Interventions: Systematic Review and Meta-Analysis.

BACKGROUND: Research has shown the effectiveness of sedentary behaviour interventions on reducing sedentary time. However, no systematic review has studied where the reduced sedentary time after such interventions is displaced to. OBJECTIVE: Our objective was to synthesize the evidence from interventions that have reduced sedentary behaviour and test the displacement of sedentary time into physical activity (light physical activity [LPA], moderate-to-vigorous physical activity [MVPA], standing, and stepping). METHODS: Two independent researchers performed a systematic search of the EBSCOhost, PubMed, Scopus, and Web of Science electronic databases. Meta-analyses were performed to examine the time reallocated from sedentary behaviour to physical activity during working time and the whole day in intervention trials (randomized/non-randomized controlled/non-controlled). RESULTS: A total of 36 studies met all the eligibility criteria and were included in the systematic review, with 26 studies included in the meta-analysis. Interventions showed a significant overall increase in worksite LPA (effect size [ES] 0.24; 95% confidence interval [CI] 0.05 to 0.43; P < 0.013) and daily LPA (ES 0.62; 95% CI 0.34 to 0.91; P = 0.001). A statistically significant increase in daily MVPA was observed (ES 0.47; 95% CI 0.26 to 0.67; P < 0.001). There was a significant overall increase in worksite standing time (ES 0.76; 95% CI 0.56 to 0.95; P < 0.001), daily standing time (ES 0.52; 95% CI 0.38 to 0.65; P < 0.001), and worksite stepping time (ES 0.12; 95% CI 0.04 to 0.20; P = 0.002). CONCLUSIONS: Effective interventions aimed at reducing sedentary behaviour result in a consistent displacement of sedentary time to LPA and standing time, both at worksites and across the whole day, whereas changes in stepping time or MVPA are dependent on the intervention setting. Strategies to reduce sedentary behaviour should not be limited to worksite settings, and further efforts may be required to promote daily MVPA. TRIAL REGISTRATION: PROSPERO registration number CRD42020153958.

Muscle-Strengthening Exercise Questionnaire (MSEQ): an assessment of concurrent validity and test-retest reliability.

OBJECTIVES: Muscle-strengthening exercise (MSE) has multiple independent health benefits and is a component of global physical activity guidelines. However, the assessment of MSE in health surveillance is often limited to the constructs of frequency (days/week), with little focus on constructs such as MSE type, muscle groups targeted and intensity. This study describes the test-retest reliability and concurrent validity of the Muscle-Strengthening Exercise Questionnaire (MSEQ), which was developed to assess multiple MSE participation constructs. METHODS: The MSEQ was developed to assess the weekly frequency, session duration and intensity, types of MSE (eg, weight machines, bodyweight exercise) and muscle groups targeted. Two convenience samples of adult participants were recruited. Test-retest reliability was completed online by 85 participants. Concurrent validity was assessed for 54 participants using an online 7-day MSE log. RESULTS: The MSEQ shows high test-retest reliability for frequency, duration and level of intensity for each of the four MSE types (using weight machines, bodyweight exercises, resistance exercises and holistic exercises), and for the four types combined (ρ range 0.76-0.91). For muscle groups targeted, the reliability ranged mostly from moderate-to-substantial for each of the four MSE types (κ range 0.44-0.78) and fair-to-moderate for the four types combined (κ range 0.35-0.51). Concurrent validity for frequency, duration and level of intensity for each of the four MSE types, and the four types combined, was moderate-to-high (ρ range 0.30-0.77). CONCLUSION: The MSEQ shows acceptable reliability and validity for four key MSE constructs. This new MSEQ survey instrument could be used to assess adults' MSE.

Physical activity and sedentary behaviour of female adolescents in Indonesia: A multi-method study on duration, pattern and context.

Background/Objective: Exploring comprehensive information on the duration, pattern and context of physical activity and sedentary behaviour is important to develop effective policies and interventions. Especially in lower- and middle-income countries, our understanding of these health-behaviours is limited. Our study aimed to investigate physical activity and sedentary behaviour of female Indonesian adolescents by using a multi-method approach. Methods: Female adolescents (n = 5; 13-15 years old) from Yogyakarta, Indonesia wore accelerometers and automated wearable cameras for four days, and completed diaries, and interviews between February and March 2020. Results: Participants' activity, especially on non-school days, was dominated by light-intensity physical activity. Four of the 5 participants did not meet the physical activity guidelines. Participants spent a great proportion of time on screen-based sedentary behaviour (school days: 83.2% of wear time; non-school days: 75.7% of wear time). During school days, most physical activity and sedentary behaviour was done at school. Screen time was mainly done on the school day evenings and weekend mornings. Participants mostly used smartphones in the bedroom and living room in a solitary environment. Interviews suggest that the high amount of screen time seemed to be influenced by a lack of awareness of current guidelines, the feeling of urgency to check information, and the lack of parental supervision. Non-screen-based sedentary behaviour comprised just over 10% of total camera images. Conclusion: The use of a multi-method approach facilitated a rich understanding of the duration, patterns, and contexts of physical activity and sedentary behaviour in participants. Future studies might consider using similar methods in a larger sample.

Using Wearable Cameras to Categorize the Type and Context of Screen-Based Behaviors Among Adolescents: Observational Study.

BACKGROUND: Automated wearable cameras present a new opportunity to accurately assess human behavior. However, this technology is seldom used in the study of adolescent's screen exposure, and the field is reliant on poor-quality self-report data. OBJECTIVE: This study aimed to examine adolescents' screen exposure by categorizing the type and context of behaviors using automated wearable cameras. METHODS: Adolescents (mean age 15.4 years, SD 1.6 years; n=10) wore a camera for 3 school evenings and 1 weekend day. The camera captured an image every 10 seconds. Fieldwork was completed between February and March 2020, and data were analyzed in August 2020. Images were date and time stamped, and coded for screen type, content, and context. RESULTS: Data representing 71,396 images were analyzed. Overall, 74.0% (52,842/71,396) of images contained screens and 16.8% (11,976/71,396) of images contained multiple screens. Most screen exposures involved television sets (25,950/71,396, 36.3%), smartphones (20,851/71,396, 29.2%), and laptop computers (15,309/71,396, 21.4%). The context of screen use differed by device type, although most screen exposures occurred at home (62,455/64,856, 96.3%) and with solitary engagement (54,430/64,856, 83.9%). The immediate after-school period saw high laptop computer use (4785/15,950, 30.0%), while smartphone use (2059/5320, 38.7%) peaked during prebedtime hours. Weekend screen exposure was high, with smartphone use (1070/1927, 55.5%) peaking in the early morning period and fluctuating throughout the day. CONCLUSIONS: There was evidence for high screen use during the after-school and weekend period, mostly through solitary engagement, and within the home environment. The findings may inform the basis of larger studies aimed at examining screen exposure in free-living conditions.

Associations between duration and volume of muscle-strengthening exercise and clinically assessed hypertension among 10 519 UK adults: a cross-sectional study.

BACKGROUND: Clinical evidence shows that muscle-strengthening exercise (MSE) is important for the treatment and management of hypertension. However, the links between MSE and hypertension in epidemiological research are currently poorly understood. This study examines the association between MSE duration and volume with clinically assessed hypertension. METHODS: Cross-sectional data (n = 10519, adults ≥ 16 years) were pooled from the Health Survey for England (2012, 2016). Self-reported MSE mode (own bodyweight; gym-based), duration, and volume were tested for associations with sphygmomanometer measured hypertension (SBP ≥ 130 mmHg or DBP ≥ 80 mmHg). Poisson regressions with robust error variance were used to calculate the prevalence ratios of hypertension (outcome variable) across MSE (exposure variables: duration (minutes [0 (reference); 10-20; 21 -59; ≥60/session]); and volume [0 (reference); low

Associations between muscle-strengthening exercise and prevalent chronic health conditions in 16,301 adults: Do session duration and weekly volume matter?

OBJECTIVES: Muscle-strengthening exercise (MSE) has multiple health benefits and is part of the global physical activity guidelines. However, with epidemiological research largely focussing on participation frequency (times/week), little is known about the health associations of other parameters. Hence, this study aimed to determine if MSE duration and volume are associated with prevalent chronic health conditions. DESIGN: Cross-sectional. METHODS: Cross-sectional data (n = 16,301 adults ≥16 years) were pooled from the Health Survey for England (2012, 2016). Respondents self-reported MSE mode (own-bodyweight, gym-based), duration and volume, and the prevalence of five chronic conditions (diabetes, anxiety/depression, heart, respiratory, or musculoskeletal condition). Poisson regressions with robust error variance were used to calculate the prevalence ratios (PR) of each chronic condition (outcome variable) across MSE parameters [exposure variables: duration (0 [reference]; 10-20; 21-59; ≥60 min/session); and volume (0 [reference]; low

Smartphone-Delivered Ecological Momentary Interventions Based on Ecological Momentary Assessments to Promote Health Behaviors: Systematic Review and Adapted Checklist for Reporting Ecological Momentary Assessment and Intervention Studies.

BACKGROUND: Healthy behaviors are crucial for maintaining a person's health and well-being. The effects of health behavior interventions are mediated by individual and contextual factors that vary over time. Recently emerging smartphone-based ecological momentary interventions (EMIs) can use real-time user reports (ecological momentary assessments [EMAs]) to trigger appropriate support when needed in daily life. OBJECTIVE: This systematic review aims to assess the characteristics of smartphone-delivered EMIs using self-reported EMAs in relation to their effects on health behaviors, user engagement, and user perspectives. METHODS: We searched MEDLINE, Embase, PsycINFO, and CINAHL in June 2019 and updated the search in March 2020. We included experimental studies that incorporated EMIs based on EMAs delivered through smartphone apps to promote health behaviors in any health domain. Studies were independently screened. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. We performed a narrative synthesis of intervention effects, user perspectives and engagement, and intervention design and characteristics. Quality appraisal was conducted for all included studies. RESULTS: We included 19 papers describing 17 unique studies and comprising 652 participants. Most studies were quasi-experimental (13/17, 76%), had small sample sizes, and great heterogeneity in intervention designs and measurements. EMIs were most popular in the mental health domain (8/17, 47%), followed by substance abuse (3/17, 18%), diet, weight loss, physical activity (4/17, 24%), and smoking (2/17, 12%). Of the 17 studies, the 4 (24%) included randomized controlled trials reported nonstatistically significant effects on health behaviors, and 4 (24%) quasi-experimental studies reported statistically significant pre-post improvements in self-reported primary outcomes, namely depressive (P<.001) and psychotic symptoms (P=.03), drinking frequency (P<.001), and eating patterns (P=.01). EMA was commonly used to capture subjective experiences as well as behaviors, whereas sensors were rarely used. Generally, users perceived EMIs to be helpful. Common suggestions for improvement included enhancing personalization, multimedia and interactive capabilities (eg, voice recording), and lowering the EMA reporting burden. EMI and EMA components were rarely reported and were not described in a standardized manner across studies, hampering progress in this field. A reporting checklist was developed to facilitate the interpretation and comparison of findings and enhance the transparency and replicability of future studies using EMAs and EMIs. CONCLUSIONS: The use of smartphone-delivered EMIs using self-reported EMAs to promote behavior change is an emerging area of research, with few studies evaluating efficacy. Such interventions could present an opportunity to enhance health but need further assessment in larger participant cohorts and well-designed evaluations following reporting checklists. Future research should explore combining self-reported EMAs of subjective experiences with objective data passively collected via sensors to promote personalization while minimizing user burden, as well as explore different EMA data collection methods (eg, chatbots). TRIAL REGISTRATION: PROSPERO CRD42019138739; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=138739.

Adolescents' physical activity and sedentary behaviour in Indonesia during the COVID-19 pandemic: a qualitative study of mothers' perspectives.

BACKGROUND: Socio-behavioural adaptations during the COVID-19 pandemic may have significantly affected adolescents' lifestyle. This study aimed to explore possible reasons affecting changes in physical activity and sedentary behaviour in Indonesian adolescents during the pandemic based on mothers' perspectives. METHODS: We recruited parents (n = 20) from the Yogyakarta region of Indonesia (July-August 2020) using purposive and snowball sampling. Individual interviews were audio-recorded, transcribed verbatim and anonymised. Data were imported into NVivo software for a reflexive thematic analysis. RESULTS: The interviews lasted between 38 and 113 min (M = 65 min). Participants' age ranged between 36 and 54 years (M = 42.6 years). Participants' children ranged in age from 12 to 15 years (M = 13.7 years, female: 9, male: 11). Themes related to changes in physical activity during the pandemic were 1) self-determination and enjoyment, 2) supports from others, and 3) physical activity facilities and equipment. Themes related to changes in sedentary behaviour during the pandemic included 1) educational demands, 2) psychological effects due to the pandemic, 3) devices and internet availability, 4) parental control, and 5) social facilitators. CONCLUSIONS: During the pandemic, mothers perceived their children to be less active and using more screen-based devices, either for educational or recreational purposes, compared to before. The present themes might be useful when developing interventions and policies promoting physical activity and reducing sedentary behaviour in adolescents. Interventions could, for example, consider increasing parents' and adolescents' awareness on current activity guidelines, providing education on healthier recreational screen time, and involving parents, peers, and teachers. Increasing the accessibility of physical activity facilities and equipment, making use of adolescents' favourite program and social media for interventions, and providing activities that are fun and enjoyable may also important.

The Relation between Physical Education Teachers' (De-)Motivating Style, Students' Motivation, and Students' Physical Activity: A Multilevel Approach.

Research suggests that physical education (PE) teachers can play a crucial role in the promotion of students' physical activity. Grounded in Self-Determination Theory, this study investigated how students' perceptions of PE teachers (de-)motivating style relate to students' device-based physical activity levels during PE. Moreover, it was examined whether students' motivation plays an intervening role in this relation and whether students' physical activity differs according to their gender and lesson topic. A sample of 302 secondary school students aged between 11 and 16 years (M = 13.05, SD = 1.04) completed a questionnaire assessing their perceptions of teachers' (de-)motivating style and their personal motivation toward PE. Students also wore ActiGraph GT3X accelerometers during the PE lesson. Multilevel structural equation modeling revealed that the teachers' motivating style had a significant positive relation with students' autonomous motivation, both at the student level and the class level, and teachers' controlling style had a significant positive relation with students' controlled motivation and amotivation at both levels. However, in terms of students' physical activity levels, students' gender, the lesson topic, and teachers' controlling style seemed to be more decisive than students' motivation and teachers' motivating style.

Is all activity equal? Associations between different domains of physical activity and depressive symptom severity among 261,121 European adults.

BACKGROUND: Physical activity is often associated with better mental health. However, there is evidence that the domain of physical activity influences the strength and direction of this association. Therefore, this study aimed to examine the associations between different domains of physical activity and depression among a large sample of adults living in the European Union. METHODS: Cross-sectional analyses were conducted on 261,121 adults, recruited in the European Health Interview Survey (wave 2). Validated items were used to assess physical activity domains (i.e., work-related, transport-related, leisure-time aerobic, and muscle-strengthening) and depression symptom severity (8-item personal health questionnaire). Generalized linear models with Poisson regressions provided adjusted prevalence ratios (APR) of depressive symptom severity categories across the physical activity domains. RESULTS: Compared to doing no physical activity, any physical effort at work (APR: 0.82-0.86), moderate, high, and very high levels of transport-related (APR: 0.69-0.83) and aerobic leisure-time activity (APR: 0.78-0.87), and 3 days/week of muscle-strengthening (APR: 0.93) were associated with a lower prevalence of mild depressive symptom severity. Moreover, doing any level of physical activity in any domain was mostly associated with a lower prevalence of moderate (APR: 0.43-0.80), moderate-severe (APR: 0.34-0.82), and severe (APR: 0.26-0.56) depressive symptoms. CONCLUSION: Favorable associations were seen between any domain (leisure-time, transport- and work-related) of physical activity and depressive symptom severity. The more severe the symptoms, the stronger the associations. Both modalities of leisure-time physical activity (aerobic and muscle-strengthening) demonstrated beneficial associations with depression, but slightly more so for aerobic physical activity.

Assessment of muscle-strengthening exercise in public health surveillance for adults: A systematic review.

There is strong scientific evidence that muscle-strengthening exercise (i.e. use of weight machines, push-ups, sit-ups) is independently associated with a reduced risk of multiple chronic diseases (e.g. diabetes, hypertension, cardiovascular disease). However, prevalence rates for meeting the muscle-strengthening exercise guideline (≥2 times/week) are significantly lower (~20%) than those reported to meet the aerobic physical activity guideline (e.g. walking, jogging, cycling) (~50%). It is therefore important to understand public health surveillance approaches to assess muscle-strengthening exercise. The aim of this review was to describe muscle-strengthening exercise assessment in public health surveillance. Informed by the PRISMA guidelines, an extensive keyword search was undertaken across 7 electronic data bases. We identified 86,672 possible articles and following screening (n = 1140 in full-text) against specific inclusion criteria (adults aged ≥18 years, English, studies containing <1000 participants), extracted data from 156 manuscripts. Fifty-eight different survey systems were identified across 17 countries. Muscle-strengthening exercise frequency (85.3%), duration (23.7%) and intensity (1.3%) were recorded. Muscle-strengthening exercise questions varied significantly, with some (11.5%) requiring a singular 'yes' vs 'no' response, while others (7.7%) sought specific details (e.g. muscle groups targeted). Assessments of duration and intensity were inconsistent. Very few studies measured the validity (0.6%) and reliability (1.3%) of muscle-strengthening exercise questions. Discrepancy exists within the current assessment systems/surveys used to assess muscle-strengthening exercise in public health surveillance. This is likely to impede efforts to identify at risk groups and trends within physical activity surveillance, and to accurately assess associations between muscle-strengthening exercise and health-related outcomes.

The epidemiology of muscle-strengthening and aerobic physical activity guideline adherence among 24,016 German adults.

Despite the 2016 German "National Recommendations for Physical Activity and Physical Activity Promotion" stating that adults (≥18 years) should engage in: [a] ≥150 minutes of aerobic moderate-to-vigorous-intensity physical activity/week (MVPA); and [b] ≥2 days/week of muscle-strengthening exercise (MSE), there is limited research on the descriptive epidemiology on the adherence to these guidelines among German adults. This study describes the prevalence and correlates of physical activity guideline adherence among a nationally representative sample of German adults. Data were drawn from the 2014 German Health Update survey, collected via a combination of web-based and mail surveys. Self-reported physical activity levels were assessed using the previously validated European Health Interview Survey Physical Activity Questionnaire. Weighted prevalence levels of the sample meeting the aerobic MVPA (≥150 minutes/week), MSE (≥2 times/week), and combined MVPA-MSE guidelines were calculated. Poisson regressions were used to assess prevalence ratios for physical activity guideline adherence categories across sociodemographic and lifestyle-related variables. Out of 24,016 participants (response rate = 27.6%), aged ≥ 18 years, 45.3% (95% CI: 44.5%-46.0%), 29.4% (95% CI: 28.7%-30.1%), and 22.6% (95% CI: 21.9%-23.2%) met the aerobic MVPA, MSE, and combined guidelines, respectively. Population sub-groups less likely to meet the combined guidelines included those with poor self-rated health, being unemployed, low socioeconomic status, being a current smoker, and those being overweight or obese. Since ~ 80% of German adults do not meet the nationally recommended combined aerobic MVPA-MSE physical activity guidelines, there is a necessity for large-scale public health interventions promoting both aerobic MVPA and MSE.

Associations of muscle-strengthening and aerobic exercise with self-reported components of sleep health among a nationally representative sample of 47,564 US adults.

OBJECTIVES: Evidence demonstrates that physical activity is favorably associated with indicators of sleep health. However, population-based studies rarely examine the relationship between different physical activity modalities (ie, aerobic exercise vs muscle-strengthening exercise) with components of sleep health. METHODS: Cross-sectional analyses were conducted on the US 2017 Behavioral Risk Factor Surveillance System. Validated items assessed self-reported moderate-to-vigorous-intensity aerobic physical activity (MVPA), muscle-strengthening exercise (MSE), sleep duration, difficulties and disorders. Poisson regression assessed prevalence ratios (PR) of 5 components of detrimental sleep health (short sleep; long sleep; poor quality sleep; observed snoring; and observed breathing stoppage) separately for adults 18-64 years and ≥65 years, across 4 categories of physical activity guideline adherence (met neither [reference]; MSE only; MVPA only; met both). RESULTS: The sample comprised 47,564 adults (mean age: 48.4 years; ±1.4; 51.6% female). Among those 18-64 years, with the exception of short sleep (4-6 hours), for all other detrimental sleep health components, the lowest PRs were observed among those meeting both MVPA-MSE guidelines. Among those aged ≥65 years, for all 5 detrimental sleep health components, compared to the other physical activity categories, the lowest PRs were observed among those meeting both MVPA-MSE guidelines. All associations remained after adjusting for potential confounders (sex, education, income, smoking, alcohol, depression, hypertension, diabetes). CONCLUSION: A physical activity routine that includes both MVPA and MSE is likely to be beneficial for better sleep health. Longitudinal studies are needed to establish the temporal relationships between MVPA/MSE guideline adherence and sleep health.

Is device-based total and domain-specific sedentary behaviour associated with psychological distress in Flemish workers?

BACKGROUND: There is increasing interest in the association between psychological distress and time spent in sedentary behaviour (e.g. sitting), a highly prevalent behaviour in modern society. The limited evidence is mixed and mainly based on studies using self-reported sedentary time. Few studies have investigated device-based total sedentary time in its association with distress. None, however, have examined device-based domain-specific sedentary time in relation to psychological distress. The aim of this study was to investigate whether device-based total and domain-specific sedentary behaviour were associated with psychological distress. METHODS: Flemish employees (n = 401; 20-64 years; 42.6% male; 83.6% had a 'physically active occupation') of seven organizations in service and production sectors participated. Sedentary behaviour (exposure) was assessed by two Axivity AX3 accelerometers (one placed on the thigh and one placed between the shoulders) for two to four consecutive working days. Based on diary completion, domain-specific sedentary behaviour (leisure vs. work) was assessed. The 12-item General Health Questionnaire was used to assess psychological distress (outcome). Adjusted hierarchical multiple regression models were conducted to report on the associations between total and domain-specific sedentary behaviour and psychological distress. RESULTS: About 35% of the sample had high levels of distress and average total sedentary time was 7.2 h/day. Device-based total sedentary behaviour [B = -0.009, 95% confidence interval (CI), -0.087 to 0.068], leisure-time (B = 0.001, 95% CI, -0.017 to 0.018) and work-related (B = 0.004, 95% CI, -0.006 to 0.015) sedentary behaviour were not significantly associated with psychological distress. CONCLUSION: This cross-sectional study examining the association between device-based total and domain-specific sedentary behaviour and psychological distress among employees showed a lack of significant findings.

Public health communication and education to promote more physical activity and less sedentary behaviour: Development and formative evaluation of the 'physical activity triangle'.

OBJECTIVE: Communication and education about health behaviours to the general population is essential in public health promotion. This paper describes the process and outcome of developing a new health education model (infographic) for physical activity (PA) and sedentary behaviour used in Flanders (Belgium). METHODS: The Flanders Institute for Healthy Living, expertise centre for public health, coordinated a process, including the evaluation of its previous education model among citizens; reviewing existing models from other countries; expert panel meetings (n = 3); and a formative evaluation (34 focus groups) among citizen with various profiles. RESULTS: The previous model was difficult to understand and not motivating. Foreign models (n = 18) were mostly expert-based (72 %), but not evaluated among citizens. Based on expert meetings, the new model includes a daily and weekly variety of activities at different volumes and intensities, sitting (interruptions), and physical and mental health benefits of PA. Based on the focus groups, no quantitative PA recommendations were integrated, and specific symbols, colours, and heart icons were crucial to illustrate different PA behaviours, volumes and intensities. PRACTICE IMPLICATIONS: Involving several key stakeholders, especially sedentary/inactive and vulnerable citizens, is suggested when developing a health model. Citizens preferred non-quantitative PA messages and quantitative messages around sitting interruptions.

Exploring contemporary screen time in Australian adolescents: A qualitative study.

ISSUE ADDRESSED: Screen time, a highly prevalent behaviour, can be detrimental to adolescent health. To better understand this health-related behaviour, this study explores the nature of adolescents' contemporary screen engagement, adding to the currently limited body of qualitative research in this area. METHODS: Sixteen adolescents (9 girls and 7 boys) aged 13-17 years from a secondary school in Queensland, Australia participated in semi-structured one-on-one interviews. All interviews were transcribed verbatim, anonymised and thematically analysed using an inductive approach. RESULTS: Smartphone use was ubiquitous, occurring mostly at home, after school, and typically used for social, entertainment and functional activities. Binge-watching and multi-screening emerged as common sedentary patterns of contemporary screen engagement, often performed solitary. Screen time appeared to be an important aspect of adolescents' social lives, while there were also some psychological, physical and behavioural concerns. Family and friends were thought to influence adolescents' screen time either directly (co-participation) or indirectly (modelling), while social smartphone notifications were said to prompt habitual, frequent and prolonged screen engagement. CONCLUSION: This study provided several new insights into the nature, functions, patterns, and benefits and concerns of adolescents' contemporary screen engagement. On the whole, adolescents engaged in a wide variety of screen-viewing practices, including newer digital media, mostly as a function to connect with friends and family. SO WHAT?: It might be desirable for screen time reduction interventions and policies to take into account the underlying social and psychological factors, and habitual nature of contemporary screen engagement among adolescents.

The epidemiology of muscle-strengthening exercise in Europe: A 28-country comparison including 280,605 adults.

OBJECTIVE: Muscle-strengthening exercise (use of weight machines, free weights, push-ups, sit-ups), has multiple independent health benefits, and is a component of the Global physical activity guidelines. However, there is currently a lack of multi-country muscle-strengthening exercise prevalence studies. This study describes the prevalence and correlates of muscle-strengthening exercise across multiple European countries. METHODS: Data were drawn from the European Health Interview Survey Wave 2 (2013-14), which included nationally representative samples (n = 3,774-24,016) from 28 European countries. Muscle-strengthening exercise was assessed using the European Health Interview Survey Physical Activity Questionnaire. Population-weighted proportions were calculated for (1) "insufficient" (0-1 days/week) or (2) "sufficient" muscle-strengthening exercise (≥2 days/week). Prevalence ratios were calculated using multivariate Poisson regression for those reporting sufficient muscle-strengthening by country and by sociodemographic/lifestyle characteristics (sex, age, education, income, self-rated health etc.). RESULTS: Data were available for 280,605 European adults aged ≥18 years. Overall, 17.3% (95% CI = 17.1%-17.5%) reported sufficient muscle-strengthening exercise (≥2 days/week). Muscle-strengthening exercise was geographically patterned with the lowest prevalence reported in South-eastern European countries (Romania, Malta and Cyprus: range: 0.7%-7.4%), and the highest prevalence in the Nordic countries (Iceland, Sweden, and Denmark: range: 34.1%-51.6%). Older age, insufficient aerobic activity, poorer self-rated health, lower income/education, being female, and being overweight/obese were significantly associated with lower likelihood of reporting sufficient muscle-strengthening exercise, independently of other characteristics. CONCLUSIONS: Most European adults do not report sufficient muscle-strengthening exercise, and prevalence estimates varied considerably across countries. Low participation in muscle-strengthening exercise is widespread across Europe, and warrants public health attention.