Obesity is one of the best-documented outcomes of screen media exposure. Many observational studies find relationships between screen media exposure and increased risks of obesity. Randomized ...controlled trials of reducing screen time in community settings have reduced weight gain in children, demonstrating a cause and effect relationship. Current evidence suggests that screen media exposure leads to obesity in children and adolescents through increased eating while viewing; exposure to high-calorie, low-nutrient food and beverage marketing that influences children's preferences, purchase requests, consumption habits; and reduced sleep duration. Some evidence also suggests promise for using interactive media to improve eating and physical activity behaviors to prevent or reduce obesity. Future interdisciplinary research is needed to examine the effects of newer mobile and other digital media exposures on obesity; to examine the effectiveness of additional interventions to mitigate the adverse effects of media exposures on obesity and possible moderators and mediators of intervention effects; to effectively use digital media interventions to prevent and reduce obesity; and to uncover the mechanisms underlying the causal relationships and interactions between obesity-related outcomes and media content, characteristics, and context.
To provide sex- and age-specific percentile values for levels of physical activity (PA) and sedentary time of European children aged 2.0-10.9 years from eight European countries (Sweden, Germany, ...Hungary, Italy, Cyprus, Spain, Belgium and Estonia).
Free-living PA and sedentary time were objectively assessed using ActiGraph GT1M or ActiTrainer activity monitors in all children who had at least 3 days' worth of valid accelerometer data, with at least 8 h of valid recording time each day. The General Additive Model for Location Scale and Shape was used for calculating percentile curves.
Reference values for PA and sedentary time in the European children according to sex and age are displayed using smoothed percentile curves for 7684 children (3842 boys and 3842 girls). The figures show similar trends in boys and girls. The percentage of children complying with recommendations regarding moderate-to-vigorous physical activity (MVPA) is also presented and varied considerably between sexes and country. For example, the percentage of study participants who were physically active (as assessed by MVPA) for 60 or more minutes per day ranged from 2.0% (Cyprus) to 14.7% (Sweden) in girls and from 9.5% (Italy) to 34.1% (Belgium) in boys.
This study provides the most up-to-date sex- and age-specific reference data on PA in young children in Europe. The percentage compliance to MVPA recommendations for these European children varied considerably between sexes and country and was generally low. These results may have important implications for public health policy and PA counselling.
The magnitude, consistency, and manner of association between sedentary time and outcomes independent of physical activity remain unclear.
To quantify the association between sedentary time and ...hospitalizations, all-cause mortality, cardiovascular disease, diabetes, and cancer in adults independent of physical activity.
English-language studies in MEDLINE, PubMed, EMBASE, CINAHL, Cochrane Library, Web of Knowledge, and Google Scholar databases were searched through August 2014 with hand-searching of in-text citations and no publication date limitations.
Studies assessing sedentary behavior in adults, adjusted for physical activity and correlated to at least 1 outcome.
Two independent reviewers performed data abstraction and quality assessment, and a third reviewer resolved inconsistencies.
Forty-seven articles met our eligibility criteria. Meta-analyses were performed on outcomes for cardiovascular disease and diabetes (14 studies), cancer (14 studies), and all-cause mortality (13 studies). Prospective cohort designs were used in all but 3 studies; sedentary times were quantified using self-report in all but 1 study. Significant hazard ratio (HR) associations were found with all-cause mortality (HR, 1.240 95% CI, 1.090 to 1.410), cardiovascular disease mortality (HR, 1.179 CI, 1.106 to 1.257), cardiovascular disease incidence (HR, 1.143 CI, 1.002 to 1.729), cancer mortality (HR, 1.173 CI, 1.108 to 1.242), cancer incidence (HR, 1.130 CI, 1.053 to 1.213), and type 2 diabetes incidence (HR, 1.910 CI, 1.642 to 2.222). Hazard ratios associated with sedentary time and outcomes were generally more pronounced at lower levels of physical activity than at higher levels.
There was marked heterogeneity in research designs and the assessment of sedentary time and physical activity.
Prolonged sedentary time was independently associated with deleterious health outcomes regardless of physical activity.
None.
The objective is to provide guidance for pregnant women and obstetric care and exercise professionals on prenatal physical activity. The outcomes evaluated were maternal, fetal or neonatal morbidity, ...or fetal mortality during and following pregnancy. Literature was retrieved through searches of MEDLINE, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Scopus and Web of Science Core Collection, CINAHL Plus with Full Text, Child Development & Adolescent Studies, Education Resources Information Center, SPORTDiscus, ClinicalTrials.gov and the Trip Database from inception up to 6 January 2017. Primary studies of any design were eligible, except case studies. Results were limited to English-language, Spanish-language or French-language materials. Articles related to maternal physical activity during pregnancy reporting on maternal, fetal or neonatal morbidity, or fetal mortality were eligible for inclusion. The quality of evidence was rated using the Grading of Recommendations Assessment, Development and Evaluation methodology. The Guidelines Consensus Panel solicited feedback from end users (obstetric care providers, exercise professionals, researchers, policy organisations, and pregnant and postpartum women). The development of these guidelines followed the Appraisal of Guidelines for Research and Evaluation II instrument. The benefits of prenatal physical activity are moderate and no harms were identified; therefore, the difference between desirable and undesirable consequences (net benefit) is expected to be moderate. The majority of stakeholders and end users indicated that following these recommendations would be feasible, acceptable and equitable. Following these recommendations is likely to require minimal resources from both individual and health systems perspectives.
•Physical activity can reduce the prevalence or severity of frailty.•Sedentary behaviors are associated with frailty independent of physical activity.•There are few clinical trials examining the ...impact of physical activity on frailty.•Interventions are needed which limit sedentary behaviors to manage frailty.
Heterogeneity in aging can be explained by frailty. Lifestyle behaviors such as physical activity can help manage frailty levels. Conversely, sedentary behaviours are associated with frailty independently of physical activity. Here, we summarize epidemiological and clinical trial evidence concerning the impact of physical activity and sedentary behaviors on frailty levels. We also analysed the National Health and Nutrition Examination Survey (NHANES) data to describe physical activity and sedentary behavior accumulation patterns across frailty levels and their impact on mortality risk. The few prospective and intervention studies demonstrate that higher physical activity levels are associated with a lower incidence of frailty. There are no interventions published which limit sedentary behaviors to manage frailty. Using the NHANES data we demonstrate that individuals are less likely to meet physical activity guidelines and are more likely to accumulate sedentary time in prolonged bouts. Prolonged sedentary bouts and total sedentary time were associated with a higher mortality risk in frail individuals but not in the fit group. Non-bouted sedentary time was not associated with mortality risk. Our review and novel data suggest that there is a need for more intervention studies which focus on increasing physical activity or minimizing sedentary time to manage frailty levels.
Epidemiological evidence is accumulating that indicates greater time spent in sedentary behavior is associated with all-cause and cardiovascular morbidity and mortality in adults such that some ...countries have disseminated broad guidelines that recommend minimizing sedentary behaviors. Research examining the possible deleterious consequences of excess sedentary behavior is rapidly evolving, with the epidemiology-based literature ahead of potential biological mechanisms that might explain the observed associations. This American Heart Association science advisory reviews the current evidence on sedentary behavior in terms of assessment methods, population prevalence, determinants, associations with cardiovascular disease incidence and mortality, potential underlying mechanisms, and interventions. Recommendations for future research on this emerging cardiovascular health topic are included. Further evidence is required to better inform public health interventions and future quantitative guidelines on sedentary behavior and cardiovascular health outcomes.
The authors' aim in this cross-sectional study was to characterize levels of objectively measured physical activity and sedentary time in adolescents from 9 European countries. The study comprised ...2,200 European adolescents (1,184 girls) participating in the HELENA cross-sectional study (2006-2008). Physical activity was measured by accelerometry and was expressed as average intensity (counts/minute) and amount of time (minutes/day) spent engaging in moderate- to vigorous-intensity physical activity (MVPA). Time spent in sedentary behaviors was also objectively measured. Cardiorespiratory fitness was measured by means of the 20-m shuttle run test. Level of maternal education was reported by the adolescents. A higher proportion of boys (56.8% of boys vs. 27.5% of girls) met the physical activity recommendations of at least 60 minutes/day of MVPA. Adolescents spent most of the registered time in sedentary behaviors (9 hours/day, or 71% of the registered time). Both average intensity and MVPA were higher in adolescents with high cardiorespiratory fitness, and sedentary time was lower in the high-fitness group. There were no physical activity or sedentary time differences between maternal education categories. These data provide an objective measure of physical activity and amount of time spent in sedentary behaviors in a relatively large number of European adolescents.
Sedentary behaviour is associated with risk of depression. We review and quantitatively summarise the evidence from observational studies in a meta-analysis.
We searched the PubMed, Web of Knowledge, ...Chinese National Knowledge Infrastructure and Wanfang databases for observational studies related to the association of sedentary behaviour and depression risk up to 15 January 2014. Summary relative risks (RRs) were estimated by the use of a random effects model.
Thirteen cross-sectional studies with 110,152 participants and 11 longitudinal studies with 83,014 participants were included in this meta-analysis. The summary RR of depression for the highest versus non-occasional/occasional sedentary behaviour was 1.25 (95% CI 1.16 to 1.35, I(2)=50.7%) for all included studies. The pooled RRs of depression for sedentary behaviour were 1.31 (95% CI 1.16 to 1.48) in cross-sectional studies and 1.14 (95% CI 1.06 to 1.21) in longitudinal studies. In subgroup analysis by different types of sedentary behaviour, the pooled RRs of depression were 1.13 (95% CI 1.06 to 1.21) for long-time TV viewing and 1.22 (95% CI 1.10 to 1.34) for prolonged computer or internet use.
This meta-analysis of observational studies indicates that sedentary behaviour is associated with increased risk of depression.
Getting enough sleep, exercising, and limiting sedentary activities can greatly contribute to disease prevention and overall health and longevity. Measuring the full 24-h activity cycle-sleep, ...sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)-may now be feasible using small wearable devices.
This study compared nine devices for accuracy in a 24-h activity measurement.
Adults (n = 40, 47% male) wore nine devices for 24 h: ActiGraph GT3X+, activPAL, Fitbit One, GENEactiv, Jawbone Up, LUMOback, Nike Fuelband, Omron pedometer, and Z-Machine. Comparisons (with standards) were made for total sleep time (Z-machine), time spent in SED (activPAL), LPA (GT3X+), MVPA (GT3X+), and steps (Omron). Analysis included mean absolute percent error, equivalence testing, and Bland-Altman plots.
Error rates ranged from 8.1% to 16.9% for sleep, 9.5% to 65.8% for SED, 19.7% to 28.0% for LPA, 51.8% to 92% for MVPA, and 14.1% to 29.9% for steps. Equivalence testing indicated that only two comparisons were significantly equivalent to standards: the LUMOback for SED and the GT3X+ for sleep. Bland-Altman plots indicated GT3X+ had the closest measurement for sleep, LUMOback for SED, GENEactiv for LPA, Fitbit for MVPA, and GT3X+ for steps.
Currently, no device accurately captures activity data across the entire 24-h day, but the future of activity measurement should aim for accurate 24-h measurement as a goal. Researchers should continue to select measurement devices on the basis of their primary outcomes of interest.
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