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.

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.

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.

P02-09 The dissemination of an effective school-based PA intervention programme: Sigue la Huella (Follow the footprint)

Background

A widespread dissemination of effective evidence-based physical activity (PA) interventions is needed whether a greater proportion of the population, who could potentially benefit from it, wants to be reached (Finch et al., 2016). ‘Sigue la Huella' (Follow the Footprint), is one of the few effective evidence-informed PA school-based interventions conducted on adolescents in Europe, with the support of the family and the community (Murillo et al., 2014). The main aim of this study is to describe and analyze the process of dissemination of this intervention program.

Methods

The ‘Sigue la Huella' was implemented at one secondary school situated in Jaca/Huesca (Spain). The Replicating Effective Programs (REP) framework was used, because provides a roadmap for disseminating effective interventions (Kilbourne et al., 2007). The intervention was delivered through workshops, ongoing technical assistance to the teachers, and the distribution of an instructional guide among the teachers and the school staff. A quasi-experimental design was adopted to examine the effect of ‘Sigue la Huella' after its dissemination process. PA was assessed using accelerometers at baseline and after the intervention of 14 weeks. In addition, we evaluated the dissemination process using the PRACTIS guide (Koorts et al., 2018).

Results

From an initial evaluation of the dissemination process, several key learnings emerged:

Conclusions

This study provides a comprehensive overview of the dissemination process of an effective school-based program identifying contextual barriers and facilitators that influence program implementation in new contexts and the direction of specific strategies to address those barriers.

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.

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.

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.

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.

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.

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.

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.

Older Adults' Perceptions of Sedentary Behavior: A Systematic Review and Thematic Synthesis of Qualitative Studies

BACKGROUND AND OBJECTIVES

Reducing sedentary behavior contributes to healthy aging. In order to develop sedentary behavior interventions, insight is needed into older adults' perceptions of (reducing) sedentary behavior. Therefore, this systematic review aims to synthesize qualitative evidence of older adults' perceptions towards (a) the concept of sedentary behavior, (b) barriers and facilitators of sedentary behavior, and (c) solutions and strategies to reduce sedentary behavior.

RESEARCH DESIGN AND METHODS

A systematic search was conducted in four electronic databases. Inclusion criteria comprised qualitative and mixed-methods studies investigating the perceptions of older adults (mean age: ≥60 years) towards (reducing) sedentary behavior. Quality of the included studies was rated using the Critical Appraisal Skills Programme (CASP) Qualitative Checklist. Relevant data on older adults' perceptions were extracted and imported into NVivo. Two independent reviewers analyzed the data by means of thematic synthesis (line-by-line coding, constructing descriptive (sub)themes, developing analytical themes).

RESULTS

Fifteen studies were included. Four analytical themes were developed to be considered when aiming to reduce sedentary behavior in older adults: the lack of knowledge on/awareness of sedentary behavior, the habitual nature of sedentary behavior, the importance of enjoyment and convenience, and the key role of aging.

DISCUSSION AND IMPLICATIONS

The reduction of older adults' sedentary behavior will likely be challenging as sedentary behavior seems to be firmly incorporated into older adults' daily routines, and strongly linked with positive reinforcement. Both aspects deserve thoughtful attention by intervention developers and health care professionals who aim to promote healthy aging by reducing sedentary behavior.

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.

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.

Screen-based behaviors in Australian adolescents: Longitudinal trends from a 4-year follow-up study

The longitudinal trends of screen time, a highly prevalent behavior in adolescents, are relatively unknown. This study examined longitudinal trends in screen time among a large sample of Australian primary school-aged children transitioning into secondary school-aged adolescence. Data were derived from the Longitudinal Study of Australian Children (LSAC). In 2010, 2179 children (49.7% boys; 10.3 ± 1.1 years) completed a time-use diary, recording their main activities during waking hours. This was repeated with the same sample in 2012 (12.4 ± 0.5 years) and 2014 (14.4 ± 0.5 years). Data were analyzed for time spent in TV viewing, computer use, electronic gaming, and social networking and online communication. Repeated-measures MANCOVA tests were performed to analyze trends in screen time. Trends were also analyzed by sex. Total screen time significantly increased (+85.9 min/day) over four years (η_p² = 0.010, P < .001), but differed by sex, with a larger increase in boys (boys: +41.6, girls: +22.7 min/day). Electronic gaming increased in boys (+43.2 min/day) and decreased in girls (-16.8 min/day). In contrast, girls reported larger increases in TV viewing (boys: +0.4, girls: +29.1 min/day), computer use (boys: +24.8, girls: +34.3 min/day) and time communicating online and social networking (boys: +4.3, girls: +15.2 min/day). To conclude, screen time among adolescents increases between the ages of 10 and 14 years, but differs by sex and screen time domain. Future screen time reduction interventions may choose to focus on recreational computer use and electronic gaming in boys and TV viewing and time spent communicating online and social networking for girls.

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.

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.

Physical Activity and Sedentary Behavior Research in Indonesian Youth: A Scoping Review

Background: This study aimed to map physical activity and sedentary behaviour research trends, designs, and topics for Indonesian youth. Methods: This review conforms to the “Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR).” A systematic search on eight platforms was performed in August 2018 and was updated in April 2020. Results: From 10,753 documents screened, 166 met the selection criteria. Over half of the studies were cross-sectional, and the majority utilized self-reported measurements (physical activity: 81.1%, sedentary behavior: 88.5%). More than two-thirds of the studies examined physical activity only (67.5%). The top three subtopics reported were prevalence/measurement, correlates, and outcomes of physical activity (28%, 24.6%, and 17%, respectively). The prevalence of “sufficient” physical activity ranges between 12.2% and 52.3%, while the prevalence of sedentary behavior ≥3 h per day ranges between 24.5% and 33.8%. Conclusions: Future studies need to focus more on intervention and validation, and research needs to be conducted more with nationally representative samples and on youth at the junior high school level. Future studies need to investigate more on psychological, cognitive, affective, social, cultural, and environmental correlates, and in-depth personal views of physical activity and sedentary behavior. More studies using device-based measurements, longitudinal designs, as well as qualitative and mixed-methods approaches are warranted.

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.

Adherence to aerobic and muscle-strengthening exercise guidelines and associations with psychological distress: A cross-sectional study of 14,050 English adults

Physical activity (PA) is beneficial for the prevention and management of psychological distress. However, no studies have investigated which combination/s of PA prescribed in the current global guidelines (i.e. aerobic moderate-to-vigorous PA [MVPA] and muscle-strengthening exercise [MSE]) are most strongly linked to reduced psychological distress. This study aimed to examine how PA guidelines adherence is associated with psychological distress. Using cross-sectional data of adults (n = 14,050) who participated in the 2012-2016 Health Survey for England, four categories of self-reported PA guidelines adherence were created: meeting none, only MSE, only aerobic MVPA, meeting both (exposure variables). Psychological distress (outcome) was measured using the General Health Questionnaire-12. The likelihood of experiencing high levels of psychological distress (cut-point of ≥4) across guidelines adherence categories was examined using logistic regression models adjusted for sociodemographic and lifestyle factors. About 17% of adults experienced high levels of psychological distress; 37.5% did not adhere to any PA guidelines (category 1), 1.3% met only MSE (category 2), 35.5% met only aerobic MVPA (category 3), and 25.7% met both guidelines (category 4). Compared to category 1, the likelihood of experiencing high psychological distress was lowest in category 4 (OR = 0.65, 95% CI: 0.54-0.77) followed by category 3 (OR = 0.78, 95% CI: 0.67-0.90), while it did not differ in category 2 (OR = 1.24, 95% CI: 0.75-2.05). This is the first study to identify the association between PA guidelines adherence and psychological distress in a large population sample. Findings suggest that meeting both aerobic MVPA and MSE guidelines might be most beneficial for mental health.

Muscle-strengthening Exercise Epidemiology: a New Frontier in Chronic Disease Prevention

This current opinion provides an overview of the emerging discipline of muscle-strengthening exercise epidemiology. First, we define muscle-strengthening exercise, and discuss its recent addition into the global physical activity guidelines, which were historically mainly focused on aerobic physical activity (walking, running, cycling etc.). Second, we provide an overview of the current clinical and epidemiological evidence on the associations between muscle-strengthening exercise and health, showing a reduced mortality risk, and beneficial cardiometabolic, musculoskeletal, functional and mental health-related outcomes. Third, we describe the latest epidemiological research on the assessment, prevalence, trends and correlates of muscle-strengthening exercise. An overview of recent population estimates suggests that the proportion of adults meeting the current muscle-strengthening exercise guideline (10-30%; ≥ 2 sessions/week) is far lower than adults reporting meeting the aerobic exercise guideline (~ 50%; ≥ 150 min/week). Fourth, we discuss the complexity of muscle-strengthening exercise promotion, highlighting the need for concurrent, coordinated, and multiple-level strategies to increase population-level uptake/adherence of this exercise modality. Last, we explore key research gaps and strategies that will advance the field of muscle-strengthening exercise epidemiology. Our objective is to provide a case for increased emphasis on the role of muscle-strengthening exercise for chronic disease prevention, and most importantly, stimulate more research in this currently understudied area of physical activity epidemiology.

Online physical activity and sedentary behaviour information for cancer survivors

PURPOSE

The purpose of this study is to assess the prevalence, content, and nature of information and/or advice regarding physical activity and sedentary behaviour available online for cancer survivors.

METHODS

A search strategy was designed to identify website links that were most likely to be accessed by cancer survivors, living in five English speaking nations, looking for information about maintaining and improving health after a cancer diagnosis. All content pertaining to physical activity and sedentary behaviour was extracted, and proportions of website links containing key information were calculated. Content analysis was performed on the data to describe the nature of information provided.

RESULTS

Of the 394 website links reviewed, 73.4% contained information about physical activity; however, most websites did not detail recommendations, strategies and potential risks of engaging in physical activity. Less than 10% of the links reviewed contained information about sedentary behaviour. Results varied according to website and cancer type.

CONCLUSIONS

Although the importance of physical activity is frequently mentioned, online content on the subject lacks comprehensive, specific advice. Health advice online for cancer survivors regarding the importance of avoiding sedentary behaviour is scarce with little to no detail on how to achieve this.

IMPLICATION OF CANCER SURVIVORS

Until website conveners improve the comprehensiveness and specificity of the information they provide, cancer survivors may find it difficult to find, via the Internet, the advice required to properly guide and facilitate their safe participation in physical activity and avoidance of sedentary behaviour.

Digital Health Interventions in Everyday Settings

Digitalisation, the use of digital technologies and platforms such as computers, websites, smartphones, and wearable devices, is everywhere in many ways [...].

Joint and dose-dependent associations between aerobic and muscle-strengthening activity with depression: A cross-sectional study of 1.48 million adults between 2011 and 2017

BACKGROUND

Research has shown that regular physical activity is key for the prevention and/or treatment of depression. However, epidemiological studies describing the associations between different physical activity modes (i.e., aerobic vs. muscle-strengthening exercise) with depression are limited.

METHODS

Cross-sectional analyses were conducted on pooled data from four U.S. health surveillance surveys (2011-2017). Validated survey items assessed self-reported moderate-to-vigorous-intensity physical activity (MVPA) and muscle-strengthening activity (MSA). Twenty groups were created, ranging from (a) "inactive" (0 MVPA min/week & MSA 0 times/week) to (xx) "most active" (≥300 MVPA min/week & MSA ≥4 times/week). Poisson regression with a robust error variance was used to assess prevalence ratios (PRs) of self-reported clinically diagnosed depression (outcome variable) across physical activity groups (exposure variables).

RESULTS

The sample contained 1,477,981 adults (≥18 years), of which 286,325 (18.0%) had depression. Compared to the reference group (i.e., no MVPA and no MSA), almost all physical activity combinations were associated with lower depression prevalence. Lowest prevalence of depression was shown for those combining sufficient MVPA-MSA (MVPA ≧300 min/week and MSA ≥2 times/week; adjusted prevalence ratio range: 0.54-0.63). All associations remained after stratification and/or adjustment for sociodemographic (age, sex, income, education), lifestyle characteristics (body mass index, self-rated health, smoking, alcohol), comorbidities (e.g., arthritis, diabetes, hypertension), and year of survey.

CONCLUSIONS

A physical activity routine that includes both aerobic and MSA is likely to be optimal for the prevention of depression. Public health approaches targeting depression should endorse joint aerobic and MSA as key lifestyle modification strategy.

Muscle Strengthening, Aerobic Exercise, and Obesity: A Pooled Analysis of 1.7 Million US Adults

OBJECTIVE

Both aerobic physical activity and muscle-strengthening exercise are recommended for obesity prevention. However, at the population level, the independent and/or combined associations of these physical activity modalities with obesity are unknown. The aim of this study was to examine the associations between aerobic physical activity and muscle-strengthening exercise with obesity among a representative sample of adults.

METHODS

Data were pooled from four US public health surveillance surveys from 2011 to 2017. Cross-sectional associations between adherence to the aerobic physical activity (≥ 150 min/wk) and muscle-strengthening exercise (≥ 2 times/wk) guidelines with different classes of BMI-defined obesity were examined using Poisson regression. Prevalence ratios are reported as both unadjusted and adjusted for sociodemographic and lifestyle characteristics.

RESULTS

Data were available for 1,677,108 adults (≥ 18 years old). Compared with meeting neither guideline (reference category), meeting both guidelines was associated with the lowest adjusted prevalence ratios (APRs) for the following: Class I obesity and above (BMI ≥ 30.0 kg/m² ), APR = 0.54 (95% CI: 0.53-0.54); Class II obesity and above (BMI ≥ 35.0 kg/m² ), APR = 0.32 (95% CI: 0.31-0.33); and Class III obesity and above (BMI ≥ 40.0 kg/m² ), APR = 0.21 (95% CI: 0.20-0.21).

CONCLUSIONS

Among nearly 1.7 million US adults, meeting both aerobic and muscle-strengthening exercise guidelines was associated with a lower obesity prevalence, and associations were more pronounced for higher obesity classes.

Who Uses Action Planning in a Web-Based Computer-Tailored Intervention to Reduce Workplace Sitting and What do Action Plans Look Like? Analyses of the Start to stand Intervention among Flemish Employees

BACKGROUND

Action planning plays an important role in many web-based behaviour change interventions. As such, it is important to identify who engages in action planning and what action plans look like. This study examines (1) attributes of users creating an action plan and (2) the content of action plans made during a web-based intervention to reduce workplace sitting.

METHODS

Users answered "what" (short standing breaks and/or longer periods of standing), "when" (working hours, work breaks, commuting), "where" (workplace, transport mode), and "how" (frequency, duration, implementation intentions) questions. MANOVA and chi-squared tests were conducted to compare those creating an action plan with those who did not. Descriptive statistics were used to examine the content of the action plans.

RESULTS

Those creating an action plan (n = 236/1,701) were significantly older, more sedentary at work, and more aware of health risks related to excessive sitting compared to those not planning (n = 1,465). The majority planned standing breaks (n = 212) every 30 minutes, and periods of standing (n = 173) for 1 to 2 hours.

CONCLUSIONS

Future interventions should promote action planning more, especially among younger employees and those with less health-related knowledge about sitting. Action plans were compatible with current sitting messages used in health promotion.

Citizen Science to Communicate about Public Health Messages: The Reach of a Playful Online Survey on Sitting Time and Physical Activity

There is a lack of research on how to communicate public health guidelines. Citizen science (CS) has been an effective way to involve the public in research. This study analyses the reach of a well-established CS experiment, launched during an annual national science event, to understand if it could be used as communication strategy for public health issues. A short playful online survey contained tailored health-related messages associated to an "animal totem" profile, based on the combination of sitting and physical activity levels (koala: high sitting, low activity; gorilla: high sitting, high activity; zebra: low sitting, low activity; bee: low sitting, high activity). Tweets, radio interviews, radio and online advertisements, press articles, and a press conference were used to promote the CS experiment. Google Analytics and Facebook Graph API (application programming interface) (use and spread of experiment) and descriptive statistics (attributes of adults completing the experiment) were used. A total of 6,246 adults completed the experiment, with a peak of views (n = 5,103) and completions (n = 1,209) a couple of days before the event. Completers were mostly female (65.8%), on average 37.5 years old, and had a healthy body mass index (23.8 kg/m²). Nearly half (46.4%) had the most beneficial profile ("bee"), 26.5% had the least healthy profile ("koala"). CS as part of a national science event is a good platform for health communication as 1 in 1,000 Flemish adults were reached. However, those completing the experiment were not representative of the general Flemish adult population and reported to be more physically active. Abbreviations: API: application programming interface; BMI: body mass index; CVD: cardiovascular disease; METs: metabolic equivalents.

The epidemiology of aerobic physical activity and muscle-strengthening activity guideline adherence among 383,928 U.S. adults

BACKGROUND

The World Health Organization's 'Global Recommendations on Physical Activity for Health' state that adults should engage in regular moderate-to-vigorous intensity aerobic physical activity (MVPA; e.g. walking, running, cycling) and muscle-strengthening activity (MSA; e.g. strength/resistance training). However, assessment of both MVPA and MSA is rare in physical activity surveillance. The aim of this study is to describe the prevalence, correlates and chronic health conditions associated with meeting the combined MVPA-MSA guidelines among a population representative sample of U.S. adults.

METHODS

In this cross-sectional study, data were drawn from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone interviews, MVPA and MSA were assessed using validated questionnaires. We calculated the proportions meeting both the global MVPA and MSA physical activity guidelines (MVPA ≥150 min/week and MSA ≥2 sessions/week). Poisson regressions with a robust error variance were used to assess: (i) prevalence ratios (PR) for meeting both guidelines across sociodemographic factors (e.g. age, sex, education, income, race/ethnicity); and (ii) PRs of 12 common chronic health conditions (e.g. diabetes, coronary heart disease, hypertension, depression) across different categories of physical activity guideline adherence (met neither [reference]; MSA only; MVPA only; met both).

RESULTS

Among 383,928 adults (aged 18-80 years), 23.5% (95% CI: 20.1, 20.6%) met the combined MVPA-MSA guidelines. Those with poorer self-rated health, older adults, women, lower education/income and current smokers were less likely to meet the combined guidelines. After adjustment for covariates (e.g. age, self-rated health, income, smoking) compared with meeting neither guidelines, MSA only and MVPA only, meeting the combined MVPA-MSA guidelines was associated with the lowest PRs for all health conditions (APR range: 0.44-0.76), and the clustering of ≥6 chronic health conditions (APR = 0.33; 95% CI: 0.31-0.35).

CONCLUSIONS

Eight out of ten U.S. adults do not meet the global physical activity guidelines. This study supports the need for comprehensive health promotion strategies to increase the uptake and adherence of MVPA-MSA among U.S. adults. Large-scale interventions should target specific population sub-groups including older adults, women, those with poorer health and lower education/income.

What factors explain socioeconomic inequalities in adults' television-related sitting time?

BACKGROUND

There are considerable socioeconomic inequalities in television-related sitting time, but there is little evidence for the explanatory mechanisms. We used a cohort of Belgian adults (25-60 years) and older adults (≥65 years) to examine the social cognitive, home environmental and health-related factors contributing to socioeconomic differences in television-related sitting.

METHODS

We included 301 adults and 258 older adults (total n = 559). Linear regression analyses were used to examine the associations of education and occupational status with television-related sitting time, adjusted for age and gender. We assessed the explanatory power of social cognitive, home environmental and health-related factors using the traditional 'change-in-estimation method'.

RESULTS

Those with low and medium education, respectively, engaged in 54 and 28 minutes per day more television-related sitting time than those with high education. We found no association between occupational status and television-related sitting time. Social cognitive factors explained 54% of the difference in television-related sitting time between those with low and high education, while home environmental factors only explained 6%, and health-related variables explained 10% of these differences.

CONCLUSION

We found no occupational inequalities in television-related sitting time. Social cognitive variables such as attitude and modelling of the partner explained a large part of the educational inequalities in television-related sitting time. If confirmed by future studies, a focus on social cognition may help reduce sedentary behaviours in low-educated adults and diminish inequalities in sedentary behaviours.

Associations between aerobic and muscle-strengthening exercise with depressive symptom severity among 17,839 U.S. adults

For the prevention and management of chronic diseases, global physical activity guidelines state that an adult should engage in regular moderate-to-vigorous aerobic physical activity (MVPA; e.g. walking, cycling, running) and muscle-strengthening exercise (MSE; e.g. strength/resistance training). However, the associations between combined MVPA-MSE with chronic health conditions are rarely examined in large population studies. In particular, little is known associations between combined MVPA-MSE with depressive disorders, one of the leading causes of disability worldwide. The aim of this study is to describe the associations between MVPA and MSE with depressive symptom severity among a large sample of U.S. adults. Data were drawn from the U.S. 2015 Behavioral Risk Factor Surveillance System. During phone interviews, MVPA, MSE and depressive symptom severity were assessed by validated questionnaires. Poisson regression with a robust error or variance were used to assess prevalence ratios (PR) of depressive symptom severity (mild, moderate, moderately severe/severe) across categories of physical activity guideline adherence (met neither [reference]; MSE only; MVPA only; met both), adjusting for a set of potential cofounders. Data were available on 17,839 adults (18-85 years). When compared with those meeting neither guideline, for mild, moderate and moderately severe/severe depressive symptoms, the PRs were lowest among meeting both guidelines (range: 0.26-0.54), followed by MVPA only (range: 0.36-0.62) and MSE only (range: 0.49-0.84). Among a large sample of U.S. adults, compared to other guideline adherence categories, meeting both MVPA-MSE guidelines was associated with a lowest likelihood of reporting depressive symptoms.

Differences in Context-Specific Sedentary Behaviors According to Weight Status in Adolescents, Adults and Seniors: A Compositional Data Analysis

To develop effective sedentary behavior interventions aimed at people who are overweight/obese, detailed insight is needed into the contexts of sedentary behavior of these people. Therefore, the aims of this study were to describe the composition of sedentary behavior and to compare context-specific sedentary behaviors between different weight groups. Cross-sectional data were used from a study conducted in 2013⁻2014 among a Flemish sample of adolescents (n = 513), adults (n = 301), and seniors (n = 258). Sixteen context-specific sedentary behaviors were assessed using a validated questionnaire during the week and weekend. Compositional descriptive statistics were performed to determine the relative contribution of context-specific sedentary behaviors in the three age groups. Compositional multivariate analysis of covariance and pairwise comparisons were conducted to examine weight group differences in context-specific sedentary behaviors. The compositional means indicated that the highest proportion of sedentary time was spent at school, at work, and while watching television. Statistically significant differences were found in the composition of sedentary behaviors between healthy weight and overweight/obese participants. In all age groups, socially engaging sedentary behaviors were more prevalent in healthy weight people, whereas socially disengaging behaviors were more prevalent in overweight/obese people. Consequently, the findings of this study suggest that future overweight/obesity interventions should no longer focus on total sedentary time, as not all context-specific sedentary behaviors are associated with overweight/obesity. Instead, it might be better to target specific contexts of sedentary behaviors-preferably those less socially engaging-when aiming to reduce overweight/obesity.

Feasibility for the Use of a Standardized Fitness Testing Protocol Among Australian Fitness Industry Professionals

PURPOSE

There is currently no standardized testing protocol for assessing clients' fitness/health within the Australian fitness industry. This study examined the perceptions of the feasibility of using a standardized testing protocol among Australian fitness industry professionals.

METHOD

In 2014, 1,206 registered fitness industry professionals (aged 17-69 years) completed an online survey. Perceived feasibility for using a standardized testing protocol was assessed based on responses to 6 items. Respondents were classified as having a high level of perceived feasibility if they reported all 6 items to be "definitely feasible." A multivariate logistic regression analysis, adjusting for demographic and fitness industry-related factors (e.g., qualification/years of experience), assessed the likelihood of having a high level of perceived feasibility.

RESULTS

Overall, 25.5% (95% CI [23.1%, 28.0%]) of the sample perceived the use of a standardized testing protocol as highly feasible. Items ranked most often as "definitely feasible" were "undertaking training to use the protocol" (55%) and "conducting follow-up testing every 6 to 12 weeks" (52%). After adjustment for the effect of confounding factors, casually employed professionals (OR = 0.63; 95% CI [0.45, 0.90]) and group instructors (OR = 0.58; 95% CI [0.41, 0.82]) were less likely to perceive standardized testing protocols as highly feasible.

CONCLUSIONS

Among a large sample of Australian fitness industry professionals, slightly more than a quarter perceived using a standardized testing protocol to be highly feasible. Group instructors and casual employees perceived lower feasibility. Further research should determine the barriers to implementing a standardized testing protocol across the fitness industry.

Effect and Process Evaluation of a Smartphone App to Promote an Active Lifestyle in Lower Educated Working Young Adults: Cluster Randomized Controlled Trial

BACKGROUND

Mobile technologies have great potential to promote an active lifestyle in lower educated working young adults, an underresearched target group at a high risk of low activity levels.

OBJECTIVE

The objective of our study was to examine the effect and process evaluation of the newly developed evidence- and theory-based smartphone app "Active Coach" on the objectively measured total daily physical activity; self-reported, context-specific physical activity; and self-reported psychosocial variables among lower educated working young adults.

METHODS

We recruited 130 lower educated working young adults in this 2-group cluster randomized controlled trial and assessed outcomes at baseline, posttest (baseline+9 weeks), and follow-up (posttest+3 months). Intervention participants (n=60) used the Active Coach app (for 9 weeks) combined with a Fitbit activity tracker. Personal goals, practical tips, and educational facts were provided to encourage physical activity. The control group received print-based generic physical activity information. Both groups wore accelerometers for objective measurement of physical activity, and individual interviews were conducted to assess the psychosocial variables and context-specific physical activity. Furthermore, intervention participants were asked process evaluation questions and generalized linear mixed models and descriptive statistics were applied.

RESULTS

No significant intervention effects were found for objectively measured physical activity, self-reported physical activity, and self-reported psychosocial variables (all P>.05). Intervention participants evaluated the Active Coach app and the combined use with the Fitbit wearable as self-explanatory (36/51, 70.6%), user friendly (40/51, 78.4%), and interesting (34/51, 66.7%). Throughout the intervention, we observed a decrease in the frequency of viewing graphical displays in the app (P<.001); reading the tips, facts, and goals (P<.05); and wearing the Fitbit wearable (P<.001). Few intervention participants found the tips and facts motivating (10/41, 24.4%), used them to be physically active (8/41, 19.6%), and thought they were tailored to their lifestyle (7/41, 17.1%).

CONCLUSIONS

The lack of significant intervention effects might be due to low continuous user engagement. Advice or feedback that was not perceived as adequately tailored and the difficulty to compete with many popular commercial apps on young people's smartphones may be responsible for a decrease in the engagement. A stand-alone app does not seem sufficient to promote an active lifestyle among lower educated working young adults; therefore, multicomponent interventions (using both technological and human support), as well as context-specific sensing to provide tailored advice, might be needed in this population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02948803; https://clinicaltrials.gov/ct2/show/results/NCT02948803 (Archived by WebCite at http://www.webcitation.org/71OPFwaoA).

How does light-intensity physical activity associate with adult cardiometabolic health and mortality? Systematic review with meta-analysis of experimental and observational studies

Aim

To assess the relationship between time spent in light physical activity and cardiometabolic health and mortality in adults.

Design

Systematic review and meta-analysis.

Data sources

Searches in Medline, Embase, PsycInfo, CINAHL and three rounds of hand searches.

Eligibility criteria for selecting studies

Experimental (including acute mechanistic studies and physical activity intervention programme) and observational studies (excluding case and case–control studies) conducted in adults (aged ≥18 years) published in English before February 2018 and reporting on the relationship between light physical activity (<3 metabolic equivalents) and cardiometabolic health outcomes or all-cause mortality.

Study appraisal and synthesis

Study quality appraisal with QUALSYST tool and random effects inverse variance meta-analysis.

Results

Seventy-two studies were eligible including 27 experimental studies (and 45 observational studies). Mechanistic experimental studies showed that short but frequent bouts of light-intensity activity throughout the day reduced postprandial glucose (−17.5%; 95% CI −26.2 to −8.7) and insulin (−25.1%; 95% CI −31.8 to –18.3) levels compared with continuous sitting, but there was very limited evidence for it affecting other cardiometabolic markers. Three light physical activity programme intervention studies (n ranging from 12 to 58) reduced adiposity, improved blood pressure and lipidaemia; the programmes consisted of activity of >150 min/week for at least 12 weeks. Six out of eight prospective observational studies that were entered in the meta-analysis reported that more time spent in daily light activity reduced risk of all-cause mortality (pooled HR 0.71; 95% CI 0.62 to 0.83).

Conclusions

Light-intensity physical activity could play a role in improving adult cardiometabolic health and reducing mortality risk. Frequent short bouts of light activity improve glycaemic control. Nevertheless, the modest volume of the prospective epidemiological evidence base and the moderate consistency between observational and laboratory evidence inhibits definitive conclusions.

A Smartphone App to Promote an Active Lifestyle in Lower-Educated Working Young Adults: Development, Usability, Acceptability, and Feasibility Study

Background

Physical activity (PA) levels are problematic in lower-educated working young adults (18-26 years). To promote PA, smartphone apps have great potential, but there is no evidence for their effectiveness in this population. To increase the likelihood that a newly developed app will be effective, formative research and user testing are required.

Objective

The aim of this study was to describe the development, usability, acceptability, and feasibility of a new theory- and evidence-based smartphone app to promote an active lifestyle in lower-educated working young adults.

Methods

The new app was developed by applying 4 steps. First, determinants important to promote an active lifestyle in this population were selected. Second, evidence-based behavior change techniques were selected to convert the determinants into practical applications. Third, a new smartphone app was developed. Fourth, volunteers (n=11, both lower and higher educated) tested the app on usability, and lower-educated working young adults (n=16) tested its acceptability and feasibility via (think aloud) interviews, a questionnaire, and Google Analytics. The app was accordingly adapted for the final version.

Results

A new Android app, Active Coach, was developed that focused on knowledge, attitude, social support, and self-efficacy (based on outcomes from step 1), and that applied self-regulation techniques (based on outcomes from step 2). The app consists of a 9-week program with personal goals, practical tips, and scientific facts to encourage an active lifestyle. To ensure all-day and automatic self-monitoring of the activity behavior, the Active Coach app works in combination with a wearable activity tracker, the Fitbit Charge. Issues detected by the usability test (eg, text errors, wrong messages) were all fixed. The acceptability and feasibility test showed that participants found the app clear, understandable, and motivating, although some aspects needed to be more personal.

Conclusions

By applying a stepwise, user-centered approach that regularly consulted the target group, the new app is adapted to their specific needs and preferences. The Active Coach app was overall positively evaluated by the lower-educated working young adults at the end of the development process.

Views of policy makers and health promotion professionals on factors facilitating implementation and maintenance of interventions and policies promoting physical activity and healthy eating: results of the DEDIPAC project

Background

The uptake, implementation, and maintenance of effective interventions promoting physical activity (PA) and a healthy diet and the implementation of policies targeting these behaviors are processes not well understood. We aimed to gain a better understanding of what health promotion professionals and policy makers think are important factors facilitating adoption, implementation, and maintenance of multi-level interventions and policies promoting healthy eating and PA in Belgium, Germany, Ireland, Norway, and Poland.

Methods

Six interventions and six policies were identified based on pre-defined criteria. Forty semi-structured interviews were conducted with stakeholders from various sectors to elicit information on factors impacting adoption, implementation, and maintenance of these interventions and policies. All interview transcripts were coded in NVivo, using a common categorization matrix. Coding in the respective countries was done by one researcher and validated by a second researcher.

Results

Active involvement of relevant stakeholders and good communication between coordinating organizations were described as important factors contributing to successful adoption and implementation of both interventions and policies. Additional facilitating factors included sufficient training of staff and tailoring of materials to match needs of various target groups. The respondents indicated that maintenance of implemented interventions/policies depended on whether they were embedded in existing or newly created organizational structures in different settings and whether continued funding was secured.

Conclusions

Despite considerable heterogeneity of interventions and health policies in the five countries, stakeholders across these countries identify similar factors facilitating adoption, implementation, and maintenance of these interventions and policies.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4929-9) contains supplementary material, which is available to authorized users.

School Gardens: A Qualitative Study on Implementation Practices

School gardens have beneficial effects on children's dietary behaviors but information on its implementation is scarce. The current study aimed to gain insight in implementation practices of school gardens and in perceptions of key members and children towards a school garden. We conducted twelve interviews involving 14 key members and five focus groups with 38 children from fifth to sixth grade (10-13 years old) in four primary schools in Ghent (Flanders, Belgium). We analyzed the interviews and focus groups in NVivo, using thematic analysis. School gardens were mainly initiated to involve children in nature, not to improve vegetable consumption. Participants were positive about having a school garden, experienced facilitating factors (e.g., adaptability of the garden, having a person responsible for the garden), but also various barriers (e.g., difficulties with startup, maintenance during summer holidays and integration in the school curriculum) and suggested some solutions (e.g., involving external organizations and parents, expanding the garden) and motivating factors for children (e.g., colorful plants, use of gloves). In order to improve implementation and to contribute to children's health, future school gardening projects should take the recommendations of key members and children into account.

Cross-Sectional Associations between Home Environmental Factors and Domain-Specific Sedentary Behaviors in Adults: The Moderating Role of Socio-Demographic Variables and BMI

Despite the negative health effects of too much sitting, the majority of adults are too sedentary. To develop effective interventions, insight is needed into home environmental correlates of adults' sedentary behaviors, and into the susceptibility of population subgroups to these home environmental cues. In total, 559 Flemish adults reported socio-demographics, weight and height, home environmental factors and domain-specific sedentary behaviors. Generalized linear modeling was conducted to examine main associations between home environmental factors and domain-specific sedentary behaviors, and to test the moderating role of socio-demographics and BMI on these associations. In case of significant interactions, stratified analyses were performed. Results showed that, among those who did use a computer/laptop during the last week, a one-unit increase in the number of computers or laptops was associated with 17% (OR = 1.17; 95% CI = 1.02, 1.34) and 24% (OR = 1.24; 95% CI = 1.08, 1.43) more minutes computer time per day, respectively. The proximity of the remote controller (p < 0.001) and the number of televisions (p = 0.03) were positively associated with television time, and the number of motorized vehicles (95% CI = 0.001, 0.12) was positively associated with the odds of participation in transport-related sitting time. The latter two associations were moderated by BMI, with significant positive associations limited to those not overweight. To conclude, home environmental factors were associated with domain-specific sedentary behaviors, especially in healthy weight adults. If confirmed by longitudinal studies, public health professionals should encourage adults to limit the number of indoor entertainment devices and motorized vehicles.

What are the working mechanisms of a web-based workplace sitting intervention targeting psychosocial factors and action planning?

Background

Office workers demonstrate high levels of sitting on workdays. As sitting is positively associated with adverse health risks in adults, a theory-driven web-based computer-tailored intervention to influence workplace sitting, named ‘Start to Stand,’ was developed. The intervention was found to be effective in reducing self-reported workplace sitting among Flemish employees. The aim of this study was to investigate through which mechanisms the web-based computer-tailored intervention influenced self-reported workplace sitting.

Methods

Employees (n = 155) participated in a clustered randomised controlled trial and reported socio-demographics (age, gender, education), work-related (hours at work, employment duration), health-related (weight and height, workplace sitting and physical activity) and psychosocial (knowledge, attitudes, self-efficacy, social support, intention regarding (changing) sitting behaviours) variables at baseline and 1-month follow-up. The product-of-coefficients test of MacKinnon based on multiple linear regression analyses was conducted to examine the mediating role of five psychosocial factors (knowledge, attitudes, self-efficacy, social support, intention). The influence of one self-regulation skill (action planning) in the association between the intervention and self-reported workplace sitting time was investigated via moderation analyses.

Results

The intervention had a positive influence on knowledge (p = 0.040), but none of the psychosocial variables did mediate the intervention effect on self-reported workplace sitting. Action planning was found to be a significant moderator (p < 0.001) as the decrease in self-reported workplace sitting only occurred in the group completing an action plan.

Conclusions

Future interventions aimed at reducing employees’ workplace sitting are suggested to focus on self-regulatory skills and promote action planning when using web-based computer-tailored advice.

Trial registration

Clinicaltrials.gov NCT02672215; (Archived by WebCite at https://clinicaltrials.gov/ct2/show/NCT02672215).

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4325-5) contains supplementary material, which is available to authorized users.

Psychosocial and environmental correlates of active and passive transport behaviors in college educated and non-college educated working young adults

Background

This study aimed to examine potential differences in walking, cycling, public transport and passive transport (car/moped/motorcycle) to work and to other destinations between college and non-college educated working young adults. Secondly, we aimed to investigate which psychosocial and environmental factors are associated with the four transport modes and whether these associations differ between college and non-college educated working young adults.

Methods

In this cross-sectional study, 224 working young adults completed an online questionnaire assessing socio-demographic variables (8 items), psychosocial variables (6 items), environmental variables (10 items) and transport mode (4 types) and duration to work/other destinations. Zero-inflated negative binomial regression models were performed in R.

Results

A trend (p<0.10) indicated that more college educated compared to non-college educated young adults participated in cycling and public transport. However, another trend indicated that cycle time and public transport trips were longer and passive transport trips were shorter in non-college compared to college educated working young adults. In all working young adults, high self-efficacy towards active transport, and high perceived benefits and low perceived barriers towards active and public transport were related to more active and public transport. High social support/norm/modeling towards active, public and passive transport was related to more active, public and passive transport. High neighborhood walkability was related to more walking and less passive transport. Only in non-college educated working young adults, feeling safe from traffic and crime in their neighborhood was related to more active and public transport and less passive transport.

Conclusions

Educational levels should be taken into account when promoting healthy transport behaviors in working young adults. Among non-college educated working young adults, focus should be on increasing active and public transport participation and on increasing neighborhood safety to increase active and public transport use. Among college educated working young adults, more minutes of active transport should be encouraged.

Socio-Ecological Variables Associated with Context-Specific Sitting Time in Belgian Older Adults: A One-Year Follow-Up Study

INTRODUCTION

Knowledge about variables associated with context-specific sitting time in older adults is limited. Therefore, this study explored cross-sectional and longitudinal associations of socio-demographic, social-cognitive, physical-environmental and health-related variables with sitting during TV viewing, computer use and motorized transport in older adults.

METHODS

A sample of Belgian older adults completed structured interviews on context-specific sitting time and associated variables using a longitudinal study design. Objective measurements of grip strength and physical performance were also completed. Complete baseline data were available of 258 participants (73.98±6.16 years) of which 229 participants remained in the study at one year follow-up (retention rate: 91.60%). Cross-sectional correlates (baseline data) and longitudinal predictors (change-scores in relation with change in sitting time) were explored through multiple linear regression analyses.

RESULTS

Per context-specific sitting time, most of the cross-sectional correlates differed from the longitudinal predictors. Increases over time in enjoyment of watching TV (+one unit), encouragement of partner to watch less TV (+one unit) and TV time of partner (+30.0 min/day) were associated with respectively 9.1 min/day (p<0.001), 16.0 min/day (p<0.001) and 12.0 min/day (p<0.001) more sitting during TV viewing at follow-up. Increases over time in enjoyment of using a computer (+one unit), the number of smartphones and tablets (+1) and computer use of the partner (+30.0 min/day) were associated with respectively 5.5 min/day (p < .01), 10.4 min/day (p < .05) and 3.0 min/day (p < .05) more sitting during computer use at follow-up. An increase over time in self-efficacy regarding taking a bicycle or walking was associated with 2.9 min/day (p < .05) less sitting during motorized transport at follow-up.

CONCLUSIONS

The results stressed the importance of looking at separate contexts of sitting. Further, the results highlighted the importance of longitudinal research in order to reveal which changes in particular variables predicted changes in context-specific sitting time. Variables at the social-cognitive level were most frequently related to context-specific sitting.

Socio-Demographic, Social-Cognitive, Health-Related and Physical Environmental Variables Associated with Context-Specific Sitting Time in Belgian Adolescents: A One-Year Follow-Up Study

INTRODUCTION

More knowledge is warranted about multilevel ecological variables associated with context-specific sitting time among adolescents. The present study explored cross-sectional and longitudinal associations of ecological domains of sedentary behaviour, including socio-demographic, social-cognitive, health-related and physical-environmental variables with sitting during TV viewing, computer use, electronic gaming and motorized transport among adolescents.

METHODS

For this longitudinal study, a sample of Belgian adolescents completed questionnaires at school on context-specific sitting time and associated ecological variables. At baseline, complete data were gathered from 513 adolescents (15.0±1.7 years). At one-year follow-up, complete data of 340 participants were available (retention rate: 66.3%). Multilevel linear regression analyses were conducted to explore cross-sectional correlates (baseline variables) and longitudinal predictors (change scores variables) of context-specific sitting time.

RESULTS

Social-cognitive correlates/predictors were most frequently associated with context-specific sitting time. Longitudinal analyses revealed that increases over time in considering it pleasant to watch TV (p < .001), in perceiving TV watching as a way to relax (p < .05), in TV time of parents/care givers (p < .01) and in TV time of siblings (p < .001) were associated with more sitting during TV viewing at follow-up. Increases over time in considering it pleasant to use a computer in leisure time (p < .01) and in the computer time of siblings (p < .001) were associated with more sitting during computer use at follow-up. None of the changes in potential predictors were significantly related to changes in sitting during motorized transport or during electronic gaming.

CONCLUSIONS

Future intervention studies aiming to decrease TV viewing and computer use should acknowledge the importance of the behaviour of siblings and the pleasure adolescents experience during these screen-related behaviours. In addition, more time parents or care givers spent sitting may lead to more sitting during TV viewing of the adolescents, so that a family-based approach may be preferable for interventions. Experimental study designs are warranted to confirm the present findings.

Physical Environmental Correlates of Domain-Specific Sedentary Behaviours across Five European Regions (the SPOTLIGHT Project)

Background

The relation between neighbourhood environmental factors and domain-specific sedentary behaviours among adults remains unclear. This study firstly aims to examine the association of perceived and objectively measured neighbourhood safety, aesthetics, destinations and functionality with transport-related, work-related and leisure-time sedentary behaviour. Secondly, the study aims to assess whether these associations are moderated by age, gender or educational level.

Methods

In 60 randomly sampled neighbourhoods from 5 urban regions in Europe (Ghent and suburbs, Paris and inner suburbs, Budapest and suburbs, the Randstad, and Greater London), a virtual audit with Google Street View was performed to assess environmental characteristics. A total of 5,205 adult inhabitants of these neighbourhoods reported socio-demographic characteristics, sedentary behaviours, and neighbourhood perceptions in an online survey. Generalized linear mixed models were conducted to examine associations between physical environmental neighbourhood factors and sedentary behaviours. Interaction terms were added to test the moderating role of individual-level socio-demographic variables.

Results

Lower levels of leisure-time sedentary behaviour (i.e. all leisure activities except television viewing and computer use) were observed among adults who perceived greater numbers of destinations such as supermarkets, recreational facilities, or restaurants in their neighbourhood, and among adults who lived in a neighbourhood with more objectively measured aesthetic features, such as trees, water areas or public parks. Lower levels of work-related sedentary behaviour were observed among adults who perceived less aesthetic features in their neighbourhood, and among adults who lived in a neighbourhood with less objectively measured destinations. Both age, gender and educational level moderated the associations between neighbourhood environmental factors and sedentary behaviours.

Conclusion

Preliminary evidence was found for associations between neighbourhood environmental factors and domain-specific sedentary behaviours among adults. However, these associations varied according to objective or subjective environmental measures. More research is needed to confirm and clarify the associations.

The associations between domain-specific sedentary behaviours and dietary habits in European adults: a cross-sectional analysis of the SPOTLIGHT survey

BACKGROUND

Sedentary behaviour has been associated with obesity and related chronic diseases. Disentangling the nature of this association is complicated due to interactions with other lifestyle factors, such as dietary habits, yet limited research has investigated the relation between domain-specific sedentary behaviours and dietary habits in adults. The aim of this paper was to examine the association between domain-specific sedentary behaviours and dietary habits in adults and to test the moderating effect of age and gender on this association.

METHODS

A total of 6,037 participants from five urban regions in Europe completed an online survey, of which 6,001 were included in the analyses. Multilevel mixed-effects logistic regression analyses were used to examine main associations and interaction effects.

RESULTS

All domain-specific sedentary behaviours, except transport-related sitting time, were significantly related to dietary habits. In general, having a higher sitting time was related to having less healthy dietary habits, especially for television viewing. Gender did not moderate any of the relations, and age was only a significant moderator in the relation between other leisure sitting time and alcohol consumption.

CONCLUSION

Domain-specific sitting behaviours were related to unhealthy dietary behaviours. However, the small effect sizes suggest that individual level behavioural interventions focusing on sedentary behaviour will not be sufficient to improve dietary habits. The fact that almost none of the associations were moderated by age or gender suggests that these associations, and possibly also the effects of interventions targeting both behaviours, may hold across age and gender groups.

Validation study of Polar V800 accelerometer

BACKGROUND

The correct quantification of physical activity (PA) and energy expenditure (EE) in daily life is an important target for researchers and professionals. The objective of this paper is to study the validity of the Polar V800 for the quantification of PA and the estimation of EE against the ActiGraph (ActiTrainer) in healthy young adults.

METHODS

Eighteen Caucasian active people (50% women) aged between 19-23 years wore an ActiTrainer on the right hip and a Polar V800 on the preferred wrist during 7 days. Paired samples t-tests were used to analyze differences in outcomes between devices, and Pearson's correlation coefficients to examine the correlation between outcomes. The agreement was studied using the Bland-Altman method. Also, the association between the difference and the magnitude of the measurement (heteroscedasticity) was examined. Sensitivity, specificity and area under the receiver operating characteristic curve (ROC-AUC value) were calculated to evaluate the ability of the devices to accurately define a person who fulfills the recommendation of 10,000 daily steps.

RESULTS

The devices significantly differed from each other on all outcomes (P<0.05), except for Polar V800's alerts vs. ActiTrainer's 1 hour sedentary bouts (P=0.595) and Polar V800's walking time vs. ActiTrainer's lifestyle time (P=0.484). Heteroscedasticity analyses were significant for all outcomes, except for Kcal and sitting time. The ROC-AUC value was fair (0.781±0.048) and the sensitivity and specificity was 98% and 58%, respectively.

CONCLUSIONS

The Polar V800 accelerometer has a comparable validity to the accelerometer in free-living conditions, regarding "1 hour sedentary bouts" and "V800's walking time vs. ActiTrainer's lifestyle time" in young adults.

Health Policy Development in Flemish Small-Sized Municipalities: A Real-World Intervention

BACKGROUND

A health promotion institute developed an intervention to support small-sized municipalities (<15,000 citizens; n = 167) in their development of a local health policy.

OBJECTIVES

To (1) find out which municipalities showed interest to participate and (2) assess the intervention effects after 1 year.

METHOD

The intervention consisted of (1) completing an online tool that generated feedback on the quality level of the health policy (9 scores) and (2) receiving advice (four contacts) from the local-regional support service for health promotion. In total 121 small-sized municipalities agreed to participate (intervention municipalities), and the nonparticipating municipalities (n = 46) were used as a comparison group. Chi-square tests were conducted to compare baseline quality scores between intervention and comparison municipalities and to assess the change (baseline to follow-up) within the intervention group.

RESULTS

At baseline, intervention municipalities had significant higher health policy quality scores compared to the comparison municipalities. Municipalities interested in the intervention mostly had already high policy scores. A significant positive shift in the quality levels was found after 1 year in the intervention municipalities.

CONCLUSION

The intervention succeeded in improving the quality levels of the local health policy, though municipalities scoring low and possibly benefiting most from the intervention need to be extra-motivated to participate.

The Effectiveness of a Web-Based Computer-Tailored Intervention on Workplace Sitting: A Randomized Controlled Trial

Background

Effective interventions to influence workplace sitting are needed, as office-based workers demonstrate high levels of continued sitting, and sitting too much is associated with adverse health effects. Therefore, we developed a theory-driven, Web-based, interactive, computer-tailored intervention aimed at reducing and interrupting sitting at work.

Objective

The objective of our study was to investigate the effects of this intervention on objectively measured sitting time, standing time, and breaks from sitting, as well as self-reported context-specific sitting among Flemish employees in a field-based approach.

Methods

Employees (n=213) participated in a 3-group randomized controlled trial that assessed outcomes at baseline, 1-month follow-up, and 3-month follow-up through self-reports. A subsample (n=122) were willing to wear an activity monitor (activPAL) from Monday to Friday. The tailored group received an automated Web-based, computer-tailored intervention including personalized feedback and tips on how to reduce or interrupt workplace sitting. The generic group received an automated Web-based generic advice with tips. The control group was a wait-list control condition, initially receiving no intervention. Intervention effects were tested with repeated-measures multivariate analysis of variance.

Results

The tailored intervention was successful in decreasing self-reported total workday sitting (time × group: P<.001), sitting at work (time × group: P<.001), and leisure time sitting (time × group: P=.03), and in increasing objectively measured breaks at work (time × group: P=.07); this was not the case in the other conditions. The changes in self-reported total nonworkday sitting, sitting during transport, television viewing, and personal computer use, objectively measured total sitting time, and sitting and standing time at work did not differ between conditions.

Conclusions

Our results point out the significance of computer tailoring for sedentary behavior and its potential use in public health promotion, as the effects of the tailored condition were superior to the generic and control conditions.

Trial Registration

Clinicaltrials.gov NCT02672215; http://clinicaltrials.gov/ct2/show/NCT02672215 (Archived by WebCite at http://www.webcitation.org/6glPFBLWv)

Mediating role of energy-balance related behaviors in the association of neighborhood socio-economic status and residential area density with BMI: The SPOTLIGHT study

OBJECTIVES

This study aimed to examine the mediating effects of energy-balance related behaviors on the association of neighborhood socio-economic status (SES) and neighborhood residential area density (RAD) with body mass index (BMI).

METHODS

In total, 6037 adults from four neighborhood types (high SES/high RAD, high SES/low RAD, low SES/high RAD, and low SES/low RAD) in five Mid-European urban regions completed an online survey asking about their energy-balance related behaviors (physical activity [PA], sedentary behavior, and dietary behavior), determinants of these behaviors and their body weight and height. MacKinnon's product-of-coefficients test was used to assess mediating effects.

RESULTS

Transport-related PA, leisure-time PA and vegetable intake seemed to mediate the association between neighborhood type and BMI. Residents from low SES/low RAD neighborhoods reported less transport-related PA, less leisure-time PA and less vegetable intake than high SES/high RAD residents, and these behaviors (i.e. transport-related PA, leisure-time PA and vegetable intake) were related to having a higher BMI.

CONCLUSION

The association between neighborhood type and BMI can be explained, at least in part, by energy-balance related behaviors.