What are the most effective behaviour change techniques to promote physical activity and/or reduce sedentary behaviour in inactive adults? A systematic review protocol The relationship between physical activity, sedentary behaviour and psychological wellbeing among adolescents A cluster-randomized controlled trial to reduce sedentary behavior and promote physical activity and health of 8-9 year olds: The Transform-Us! Study A systematic review of school-based interventions targeting physical activity and sedentary behaviour among older adolescents A behaviour change intervention to reduce sedentary time in people with chronic obstructive pulmonary disease: protocol for a randomised controlled trial. Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers Trends in physical activity and sedentary behaviour in adolescence: ethnic and socioeconomic differences Energy balance-related behaviours associated with overweight and obesity in preschool children: a systematic review of prospective studies. Physical activity, sedentary behavior, and cause-specific mortality in black and white adults in the Southern Community Cohort Study. Effect of intervention aimed at increasing physical activity, reducing sedentary behaviour, and increasing fruit and vegetable consumption in children: Active for Life Year 5 (AFLY5) school based cluster randomised controlled trial Do sugar-sweetened beverages cause adverse health outcomes in children? A systematic review protocol The ProActive trial protocol – a randomised controlled trial of the efficacy of a family-based, domiciliary intervention programme to increase physical activity among individuals at high risk of diabetes [ISRCTN61323766] A Randomised Controlled Trial to Reduce Sedentary Time in Young Adults at Risk of Type 2 Diabetes Mellitus: Project STAND (Sedentary Time ANd Diabetes) The Active for Life Year 5 (AFLY5) school based cluster randomised controlled trial: study protocol for a randomized controlled trial Association of dietary habits with levels of physical activity and screen time among adolescents living in Saudi Arabia. Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults Normal weight children have higher cognitive performance – Independent of physical activity, sleep, and diet Randomised controlled trial of primary school based intervention to reduce risk factors for obesity Compliance with the Australian national physical activity guidelines for children: relationship to overweight status. Determinants of sufficient daily activity in Australian primary school children. Effectiveness of parent‐centred interventions for the prevention and treatment of childhood overweight and obesity in community settings: a systematic review Reducing office workers’ sitting time: rationale and study design for the Stand Up Victoria cluster randomized trial The effect of a healthy lifestyle programme on 8–9 year olds from social disadvantage
Introduction Large proportions of the population are not meeting recommended levels of physical activity and have increasingly sedentary lifestyles . Low levels of physical activity are predictive of poor health outcomes and time spent sedentary is related to a host of risk factors independently of physical activity levels . Building an evidence base of the best approaches to intervene in the lifestyles of inactive individuals is crucial in preventing long-term disease , disability and higher mortality rates . Methods and analysis Systematic search es will be conducted on all relevant data bases ( eg , PubMed , Scopus , CINAHL , PsycINFO ) . Studies will be included if they assess interventions aim ed at changing physical activity or sedentary behaviour levels in adults ( over 18 ) who are inactive and do not suffer from chronic conditions . Studies must also be r and omised controlled trials ( RCTs ) , have a primary outcome of physical activity or sedentary behaviour , and measure outcomes at least 6 months after intervention completion . Studies will be coded using the Behaviour Change Technique ( BCT ) taxonomy v1 and Template for Intervention Description and Replication ( TIDieR ) guidelines . 2 review ers will independently screen full-text articles and extract data on study characteristics , participants , BCTs , intervention features and outcome measures . Study quality will also be assessed independently by 2 review ers using the Cochrane risk of bias tool . A meta- analysis will be considered if there is sufficient homogeneity across outcomes . GRADE criteria will be used to assess quality of evidence . Dissemination This will be the first review to systematic ally appraise interventions aim ed at changing the physical activity or sedentary behaviour of inactive individuals using RCT design s with a 6-month follow-up post-intervention . This review will better inform intervention design ers targeting inactive population s and inform the design of a future complex intervention . Review registration number This protocol was registered with the International Prospect i ve Register of Systematic Review s ( PROSPERO ) on 17 October 2014 ( registration number : CRD42014014321 ) Background Previous studies examining the relationship between physical activity levels and broad-based measures of psychological wellbeing in adolescents have been limited by not controlling for potentially confounding variables . The present study examined the relationship between adolescents ’ self-reported physical activity level , sedentary behaviour and psychological wellbeing ; while controlling for a broad range of sociodemographic , health and developmental factors . Methods The study entailed a  cross-sectional school-based survey in ten British towns . Two thous and six hundred and twenty three adolescents ( aged 13–16 years ) reported physical activity levels , patterns of sedentary behaviour  ( TV/computer/video usage )  and completed the strengths and difficulties question naire ( SDQ ) .  Results Lower levels of self-reported physical activity and higher levels of sedentary behaviour showed grade d associations with higher SDQ total difficulties scores , both for boys ( P < 0.001 ) and girls ( P < 0.02 ) after adjustment for age and town . Additional adjustment for social class , number of parents , predicted school examination results , body mass index , ethnicity , alcohol intake and smoking status had little effect on these findings . Conclusions Low levels of self-reported physical activity are independently associated with diminished psychological wellbeing  among adolescents . Longitudinal studies may provide further insights into the relationship between wellbeing and activity levels in this population . Ultimately , r and omised controlled trials are needed to evaluate the effects of increasing physical activity on psychological wellbeing among adolescents Background Physical activity ( PA ) is associated with positive cardio-metabolic health and emerging evidence suggests sedentary behavior ( SB ) may be detrimental to children 's health independent of PA . The primary aim of the Transform-Us ! study is to determine whether an 18-month , behavioral and environmental intervention in the school and family setting s results in higher levels of PA and lower rates of SB among 8 - 9 year old children compared with usual practice ( post-intervention and 12-months follow-up ) . The secondary aims are to determine the independent and combined effects of PA and SB on  children 's cardio-metabolic health risk factors ; identify the factors that mediate the success of the intervention ; and determine whether the intervention is cost-effective . Methods / design A four-arm cluster-r and omized controlled trial ( RCT ) with a 2 × 2 factorial design , with schools as the unit of r and omization . Twenty schools will be allocated to one of four intervention groups , sedentary behavior ( SB-I ) , physical activity ( PA-I ) , combined SB and PA ( SB+PA-I ) or current practice control ( C ) , which will be evaluated among approximately 600 children aged 8 - 9 years in school year 3 living in Melbourne , Australia . All children in year 3 at intervention schools in 2010 ( 8 - 9 years ) will receive the intervention over an 18-month period with a maintenance ' booster ' delivered in 2012 and children at all schools will be invited to participate in the evaluation assessment s. To maximize the sample and to capture new students arriving at intervention and control schools , recruitment will be on-going up to the post-intervention time point . Primary outcomes are time spent sitting and in PA assessed via accelerometers and inclinometers and survey . Discussion To our knowledge , Transform-Us ! is the first RCT to examine the effectiveness of intervention strategies for reducing children 's overall sedentary time , promoting PA and optimizing health outcomes . The integration of consistent strategies and messages to children from teachers and parents in both school and family setting s is a critical component of this study , and if shown to be effective , may have a significant impact on educational policies as well as on pedagogical and parenting practice s . Trial registration ACTRN12609000715279 ; Current Controlled Trials IS RCT ABSTRACT Lack of  physical activity  (  PA  ) and high levels of sedentary behaviour ( SB ) have been associated with health problems . This systematic review evaluates the effectiveness of school-based interventions to increase PA  and decrease SB  among 15–19-year-old adolescents , and examines whether intervention characteristics ( intervention length , delivery mode and intervention provider ) and intervention content ( i.e. behaviour change techniques , BCTs ) are related to intervention effectiveness . A systematic search of r and omised or cluster r and omised controlled trials with outcome measures of PA and /or SB rendered 10 results . Risk of bias was assessed using the Cochrane risk of bias tool . Intervention content was coded using Behaviour Change Technique Taxonomy v1 . Seven out of 10 studies reported significant increases in PA . Effects were generally small and short-term ( Cohen 's d ranged from 0.132 to 0.659 ) . Two out of four studies that measured SB reported significant reductions in SB . Interventions that increased PA  included a higher number of BCTs , specific BCTs ( e.g. , goal setting , action planning and self-monitoring ) , and were delivered by research staff . Intervention length and mode of delivery were unrelated to effectiveness . More studies are needed that evaluate long-term intervention effectiveness and target SBs among older adolescents INTRODUCTION Replacing sedentary behaviour with light intensity physical activity ( ie , activities classified as less than three metabolic equivalents , such as slow-paced walking ) may be a more realistic strategy for reducing cardiometabolic risk in people with chronic obstructive pulmonary disease than only aim ing to increase levels of moderate-vigorous intensity physical activity . Behaviour change interventions to reduce sedentary behaviour in people with chronic obstructive pulmonary disease have not yet been developed or tested . RESEARCH QUESTIONS Is a 6-week behaviour change intervention effective and feasible in reducing sedentary time in people with chronic obstructive pulmonary disease ? DESIGN This study will be a multi-centre , r and omised , controlled trial with concealed allocation , assessor blinding , and intention-to-treat analysis , comparing a 6-week behaviour change intervention aim ed at reducing sedentary time with a sham intervention in people with chronic obstructive pulmonary disease . PARTICIPANTS AND SETTING Seventy participants will be recruited from the waiting lists for pulmonary rehabilitation programs at Royal Prince Alfred Hospital and Prince of Wales Hospital , Sydney , Australia . INTERVENTION The behaviour change intervention aims to reduce sedentary time through a process of guided goal setting with participants to achieve two target behaviours : ( 1 ) replace sitting and lying down with light-intensity physical activity where possible , and ( 2 ) st and up and move for 2minutes after 30minutes of continuous sedentary time . Three face-to-face sessions and three phone sessions will be held with a physiotherapist over the 6-week intervention period . The ' capability ' , ' opportunity ' , ' motivation ' and ' behaviour ' ( COM-B ) model will be applied to each participant to determine which components of behaviour ( capability , opportunity or motivation ) need to change in order to reduce sedentary time . Based on this ' behavioural diagnosis ' , the Behaviour Change Wheel will be used to systematic ally select appropriate behaviour change techniques to assist participants in achieving their weekly goals . Behaviour change techniques will include providing information about the health consequences of sedentary behaviour , self-monitoring and review of weekly goals , problem-solving of barriers to achieving weekly goals , and providing feedback on sedentary time using the Jawbone UP3 activity monitor . CONTROL The sham intervention will consist of weekly phone calls for 6 weeks , to enquire whether the participants ' health status has changed over the intervention period ( eg , hospitalised for an acute exacerbation ) . No instructions regarding physical activity or exercise will be given . MEASUREMENTS Outcomes will be assessed at baseline , at the end of the 6-week intervention period , and at the 3-month follow-up . Primary outcome measures will be : ( 1 ) total sedentary time , including the pattern of accumulation of sedentary time , assessed by the activPAL3 activity monitor , and ( 2 ) feasibility of the intervention assessed by uptake and retention of participants , participant compliance , self-reported achievement of weekly goals , and adverse events . Secondary outcome measures will include functional exercise capacity , health-related quality of life , domain-specific and behaviour-specific sedentary time , patient activation , and anxiety and depression .  Semi-structured interviews will be conducted with participants who receive the behaviour change intervention to explore acceptability and satisfaction with the different components of the intervention . ANALYSIS Analysis of covariance ( ANCOVA ) will be used to calculate between-group comparisons of total sedentary time and the number of bouts of sedentary time>30minutes after adjusting baseline values . Uncertainty about the size of the mean between-group differences will be quantified with 95 % CI . Within-group comparisons will be examined using paired t-tests and described as mean differences with 95 % CIs . Secondary outcome measures will be analysed similarly . The feasibility measures will be analysed descriptively . Semi-structured interviews will be conducted until data saturation is achieved and there are no new emerging themes . De-identified interview transcripts will be coded independently by two research ers and analysed alongside data collection using the COM-B model as a thematic framework . DISCUSSION / SIGNIFICANCE If behaviour change interventions are found to be an effective and feasible method for reducing sedentary time , such interventions may be used to reduce cardiometabolic risk in people with chronic obstructive pulmonary disease . An approach that emphasises participation in light-intensity physical activity may increase the confidence and willingness of people with chronic obstructive pulmonary disease to engage in more intense physical activity , and may serve as an intermediate goal to increase uptake of pulmonary rehabilitation Purpose Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes . We aim ed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and question naire-based activity measures . Methods  Physical activity and sedentary behaviour  were assessed in 317 adults by 7-day accelerometry and International Physical Activity Question naire ( IPAQ ) . Fasting blood was taken to determine insulin , glucose , triglyceride and total , LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance ( HOMAIR ) . Waist circumference , BMI , body fat percentage and blood pressure were also measured . Results For both accelerometer-derived sedentary time ( < 100 counts.min−1 ) and IPAQ-reported sitting time significant positive ( negative for HDL cholesterol ) relationships were observed with all measured risk factors – i.e. increased sedentary behaviour was associated with increased risk ( all p≤0.01 ) . However , for HOMAIR and insulin the regression coefficients were > 50 % lower for the IPAQ-reported compared to the accelerometer-derived measure ( p<0.0001 for both interactions ) . The relationships for moderate-to-vigorous physical activity ( MVPA ) and risk factors were less strong than those observed for sedentary behaviours , but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose , and insulin and HOMAIR values ( all p<0.05 ) . For accelerometer-derived MVPA only , additional negative relationships were seen with triglyceride , total cholesterol and LDL cholesterol concentrations , BMI , waist circumference and percentage body fat , and a positive relationship was evident with HDL cholesterol ( p = 0.0002 ) . Regression coefficients for HOMAIR , insulin and triglyceride were 43–50 % lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure ( all p≤0.01 ) . Conclusion Using the IPAQ to determine sitting time and MVPA reveals some , but not all , relationships between these activity measures and metabolic and vascular disease risk factors . Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors Objective : To assess developmental trends in physical activity and sedentary behaviour in British adolescents in relation to sex , ethnicity and socioeconomic status ( SES ) . Design : A 5-year longitudinal study of a diverse cohort of students aged 11–12 years at baseline in 1999 . Setting : 36 London schools sample d using a stratified r and om sampling procedure . Participants : A total of 5863 students categorised as white , black or Asian , and stratified for SES using the Townsend Index  . Main outcome measures : Number of days per week of vigorous activity leading to sweating and breathing hard . Hours of sedentary behaviour , including watching television and playing video games .  Data were analysed using multilevel , linear , mixed models . Results : Marked reductions in physical activity and increases in sedentary behaviour were noticed between ages 11–12 and 15–16 years . Boys were more active than girls , and the decline in physical activity was greater in girls ( 46 % reduction ) than in boys ( 23 % ) . Asian students were less active than whites , and this was also true of black girls but not boys . Black students were more sedentary than white students . Levels of sedentary behaviour were greater in respondents from lower SES . Most differences between ethnic and SES groups were present at age 11 years , and did not evolve over the teenage years . Conclusions : Physical activity declines and sedentary behaviour becomes more common during adolescence . Ethnic and SES differences are observed in physical activity and sedentary behaviour in British youth that anticipate adult variations in adiposity and cardiovascular disease risk . These are largely established by age 11–12 years , so reversing these patterns requires earlier intervention The current review aim ed to systematic ally identify dietary , physical activity and sedentary behaviours in preschool children ( 4 - 6 years of age ) that are prospect ively related to overweight or obesity later in childhood . Prospect i ve studies published between January 1990 and June 2010 were selected from search es in PubMed , EMBASE , PsycINFO , CINAHL and Cochrane Library . Studies examining the prospect i ve association between at least one relevant behaviour measured during preschool period ( children aged 4 - 6 years at baseline ) in relation to at least one anthropometric measurement at follow-up ( age < 18 years ) were included . Harvest plots were used to summarize the results and draw conclusions from the evidence . Of the 8,718 retrieved papers , 23 papers reporting on 15 different study sample s were included in this review . Strong evidence was found for an inverse association between total physical activity and overweight . Moderate evidence was observed for a positive association between television viewing and overweight . Because of the heterogeneity in the assessed dietary behaviours , insufficient evidence was found for an association between  dietary intake or specific dietary behaviours and overweight . These results suggest that interventions aim ing to prevent overweight among preschool children should focus on promotion of total physical activity and limitation of screen time and that further research is needed to establish whether and which dietary behaviours are important for obesity prevention in this age group . However , despite the lack of evidence for dietary behaviours from the present review , future interventions may already target specific dietary behaviours that are highly prevalent and for which there a clear rationale as well as preliminary evidence that these behaviours are associated with overweight There is limited evidence demonstrating the benefits of physical activity with regard to mortality risk or the harms associated with sedentary behavior in black adults , so we examined the relationships between these health behaviors and cause-specific mortality in a prospect i ve study that had a large proportion of black adults . Participants ( 40 - 79 years of age ) enrolled in the Southern Community Cohort Study between 2002 and 2009 ( n = 63,308 ) were prospect ively followed over 6.4 years , and 3,613 and 1,394 deaths occurred in blacks and whites , respectively . Black adults who reported the highest overall physical activity level ( ≥32.3 metabolic equivalent-hours/day vs. < 9.7 metabolic equivalent-hours/day ) had lower risks of death from all causes ( hazard ratio ( HR ) = 0.76 . 95 % confidence interval ( CI ) : 0.69 , 0.85 ) , cardiovascular disease ( HR = 0.81 , 95 % CI : 0.67 , 0.98 ) , and cancer ( HR = 0.76 , 95 % CI : 0.62 , 0.94 ) . In whites , a higher physical activity level was associated with a lower risk of death from all causes ( HR = 0.76 , 95 % CI : 0.64 , 0.90 ) and cardiovascular disease ( HR = 0.69 , 95 % CI : 0.49 , 0.99 ) but not cancer ( HR = 0.95 , 95 % CI : 0.67 , 1.34 ) . Spending more time being sedentary ( > 12 hours/day vs. < 5.76 hours/day ) was associated with a 20%-25 % increased risk of all-cause mortality in blacks and whites . Blacks who reported the most time spent being sedentary ( ≥10.5 hours/day ) and lowest level of physical activity ( < 12.6 metabolic equivalent-hours/day ) had a greater risk of death ( HR = 1.47 , 95 % CI : 1.25 , 1.71 ) . Our study provides evidence that suggests that health promotion efforts to increase physical activity level and decrease  sedentary time could help reduce mortality risk in black adults Objective To investigate the effectiveness of a school based intervention to increase physical activity , reduce sedentary behaviour , and increase fruit and vegetable consumption in children . Design Cluster r and omised controlled trial . Setting 60 primary schools in the south west of Engl and . Participants Primary school children who were in school year 4 ( age 8 - 9 years ) at recruitment and baseline assessment , in year 5 during the intervention , and at the end of year 5 ( age 9 - 10 ) at follow-up assessment . Intervention The Active for Life Year 5 ( AFLY5 ) intervention consisted of teacher training , provision of lesson and child-parent interactive homework plans , all material s required for lessons and homework , and written material s for school newsletters and parents . The intervention was delivered when children were in school year 5 ( age 9 - 10 years ) . Schools allocated to control received st and ard teaching . Main outcome measures The pre-specified primary outcomes were accelerometer assessed minutes of moderate to vigorous physical activity per day , accelerometer assessed minutes of sedentary behaviour per day , and reported daily consumption of servings of fruit and vegetables . Results 60 schools with more than 2221 children were recruited ; valid data were available for fruit and vegetable consumption for 2121 children , for accelerometer assessed physical activity and sedentary behaviour for 1252 children , and for secondary outcomes for between 1825 and 2212 children for the main analyses . None of the three primary outcomes differed between children in schools allocated to the AFLY5 intervention and those allocated to the control group . The difference in means comparing the intervention group with the control group was –1.35 ( 95 % confidence interval –5.29 to 2.59 ) minutes per day for moderate to vigorous physical activity , –0.11 ( –9.71 to 9.49 ) minutes per day for sedentary behaviour , and 0.08 ( –0.12 to 0.28 ) servings per day for fruit and vegetable consumption . The intervention was effective for three out of nine of the secondary outcomes after multiple testing was taken into account : self reported time spent in screen viewing at the weekend ( –21 ( –37 to –4 ) minutes per day ) , self reported servings of snacks per day ( –0.22 ( –0.38 to –0.05 ) ) , and servings of high energy drinks per day ( –0.26 ( –0.43 to –0.10 ) ) were all reduced . Results from a series of sensitivity analyses testing different assumptions about missing data and from per protocol analyses produced similar results . Conclusion The findings suggest that the AFLY5 school based intervention is not effective at increasing levels of physical activity , decreasing sedentary behaviour , and increasing fruit and vegetable consumption in primary school children . Change in these activities may require more intensive behavioural interventions with children or upstream interventions at the family and societal level , as well as at the school environment level . These findings have relevance for research ers , policy makers , public health practitioners , and doctors who are involved in health promotion , policy making , and commissioning services . Trial registration Current Controlled Trials IS RCT N50133740 Background Cardiovascular disease and type 2 diabetes are examples of chronic diseases that impose significant morbidity and mortality in the general population worldwide . Most chronic diseases are associated with underlying preventable risk factors , such as elevated blood pressure , high blood glucose or glucose intolerance , high lipid levels , physical inactivity , excessive sedentary behaviours , and overweight/obesity . The occurrence of intermediate outcomes during childhood increases the risk of disease in adulthood . Sugar-sweetened beverages are known to be significant sources of additional caloric intake , and given recent attention to their contribution in the development of chronic diseases , a systematic review is warranted . We will assess whether the consumption of sugar-sweetened beverages in children is associated with adverse health outcomes and what the potential moderating factors are . Methods / Design Of interest are studies addressing sugar-sweetened beverage consumption , taking a broad perspective . Both direct consumption studies as well as those evaluating interventions that influence consumption ( e.g. school policy , educational ) will be relevant . Non-specific or multi-faceted behavioural , educational , or policy interventions may also be included subject to the level of evidence that exists for the other interventions /exposures . Comparisons of interest and endpoints of interest are pre-specified . We will include r and omized controlled trials , controlled clinical trials , interrupted time series studies , controlled before-after studies , prospect i ve and retrospective comparative cohort studies , case – control studies , and nested case – control design s. The MEDLINE ® , Embase , The Cochrane Library , CINAHL , ERIC , and PsycINFO ® data bases and grey literature sources will be search ed . The processes for selecting studies , abstract ing data , and resolving conflicts are described . We will assess risk of bias using design -specific tools . To determine sets of confounding variables that should be adjusted for , we have developed causal directed acyclic graphs and will use those to inform our risk of bias assessment s. Meta- analysis will be conducted where appropriate ; parameters for exploring statistical heterogeneity and effect modifiers are pre-specified . The Grading of Recommendations Assessment , Development and Evaluation ( GRADE ) approach will be used to determine the quality of evidence for outcomes . Systematic review registration PROSPERO CRD42014009641 Background Increasing prevalence of obesity and disorders associated with sedentary living constitute a major global public health problem . While previous evaluations of interventions to increase  physical activity  have involved communities or individuals with established disease , less attention has been given to interventions for individuals at risk of disease . Methods / design ProActive aims to evaluate the efficacy of a theoretical , evidence - and family-based intervention programme to increase physical activity  in a sedentary population , defined as being at-risk through having a parental family history of diabetes . Primary care diabetes or family history registers were used to recruit 365 individuals aged 30–50 years , screened for activity level . Participants were assigned by central r and omisation to three intervention programmes : brief written advice ( comparison group ) , or a psychologically based behavioural change programme , delivered either by telephone ( distance group ) or face-to-face in the family home over one year . The protocol -driven intervention programme is delivered by trained facilitators , and aims to support increases in physical activity through the introduction and facilitation of a range of self-regulatory skills ( e.g. goal setting ) . The primary outcome is daytime energy expenditure and its ratio to resting energy expenditure , measured at baseline and one year using individually calibrated heart rate monitoring . Secondary measures include self-report of individual and family activity , psychological mediators of behaviour change , physiological and biochemical correlates , acceptability , and costs , measured at baseline , six months and one year . The primary intention to treat analysis will compare groups at one-year post r and omisation . Estimation of the impact on diabetes incidence will be modelled using data from a parallel ten-year cohort study using similar measures . Discussion ProActiveis the first efficacy trial of an intervention programme to promote physical activity in a defined high-risk group accessible through primary care . The intervention programme is based on psychological theory and evidence ; it introduces and facilitates the use of self-regulatory skills to support behaviour change and maintenance . The trial addresses a range of method ological weaknesses in the field by careful specification and quality assurance of the intervention programme , precise characterisation of participants , year-long follow-up and objective measurement of physical activity . Due to report in 2005 , ProActivewill provide estimates of the extent to which this approach could assist at-risk groups who could benefit from changes in behaviours affecting health , and inform future pragmatic trials Aims Type 2 diabetes mellitus ( T2DM ) , a serious and prevalent chronic disease , is traditionally associated with older age . However , due to the rising rates of obesity and sedentary lifestyles , it is increasingly being diagnosed in the younger population . Sedentary ( sitting ) behaviour has been shown to be associated with greater risk of cardio-metabolic health outcomes , including T2DM . Little is known about effective interventions to reduce sedentary behaviour in younger adults at risk of T2DM . We aim ed to investigate , through a r and omised controlled trial ( RCT ) design , whether a group-based structured education workshop focused on sitting reduction , with self-monitoring , reduced sitting time . Methods Adults aged 18–40 years who were either overweight ( with an additional risk factor for T2DM ) or obese were recruited for the Sedentary Time ANd Diabetes ( ST AND ) RCT . The intervention programme comprised of a 3-hour group-based structured education workshop , use of a self-monitoring tool , and follow-up motivational phone call . Data were collected at three time points : baseline , 3 and 12 months after baseline . The primary outcome measure was accelerometer-assessed sedentary behaviour after 12 months . Secondary outcomes included other objective ( activPAL ) and self-reported measures of sedentary behaviour and physical activity , and biochemical , anthropometric , and psycho-social variables . Results 187 individuals ( 69 % female ; mean age 33 years ; mean BMI 35 kg/m2 ) were r and omised to intervention and control groups . 12 month data , when analysed using intention-to-treat analysis ( ITT ) and per- protocol analyses , showed no significant difference in the primary outcome variable , nor in the majority of the secondary outcome measures . Conclusions A structured education intervention design ed to reduce sitting in young adults at risk of T2DM was not successful in changing behaviour at 12 months . Lack of change may be due to the brief nature of such an intervention and lack of focus on environmental change . Moreover , some participants reported a focus on physical activity rather than reductions in sitting per se . The habitual nature of sedentary behaviour means that behaviour change is challenging . Trial Registration Controlled-Trials.com IS RCT Background Low levels of physical activity , high levels of sedentary behaviour and low levels of fruit and vegetable consumption are common in children and are associated with adverse health outcomes . The aim of this paper is to describe the protocol for a cluster r and omised controlled trial ( RCT ) design ed to evaluate a school-based intervention that aims to increase levels of physical activity  , decrease  sedentary behaviour  and increase consumption of fruit and vegetables in school children . Methods / design The Active for Life Year 5 ( AFLY5 ) study is a school-based , cluster RCT that targets school children in Year 5 ( age 9 - 10 years ) . All state junior/ primary schools in the area covered by Bristol City and North Somerset Council are invited to participate ; special schools are excluded . Eligible schools are r and omised to one of two arms : intervention arm ( receive the intervention 2011 - 2012 ) and control arm ( receive the intervention after the final follow-up assessment , 2013 - 2014 ) . The primary outcomes of the trial are levels of accelerometer assessed physical activity and sedentary behaviour and question naire assessed fruit and vegetable consumption . A number of secondary outcomes will also be measured , including body mass index , waist circumference and overweight/obesity . Outcomes will be assessed at baseline ( prior to intervention when the children are in Year 4 ) , at the end of intervention ' immediate follow-up ' and ' 12 months long-term ' follow-up . We will use r and om effects linear and logistic regression models to compare outcomes by r and omised arm . The economic evaluation from a societal perspective will take the form of a cost consequence analysis . Data from focus groups and interviews with pupils , parents and teachers will be used to increase underst and ing of how the intervention has any effect and is integrated into normal school activity . Discussion The results of the trial will provide information about the public health effectiveness of a school-based intervention aim ed at improving levels of physical activity , sedentary behaviour and diet in children . Trial registration IS RCT BACKGROUND Underst and ing the inter-relationships between lifestyle factors in youth is important with respect to the development of effective promotional programmes for healthy eating and active living . The present study aim ed to explore the associations of dietary habits ( DH ) with physical activity ( PA ) and screen time ( ST )  among Saudi adolescents aged between 15 and 19 years of age relative to gender . METHODS Data were obtained from the Arab Teens Lifestyle Study , a school-based multicentre lifestyle study conducted in 2009/2010 in three major cities in Saudi Arabia . A multistage stratified cluster r and om sampling technique was used . The number of participants with complete data for  DH  and  PA  was 2886 and the respective number for DH and ST was 2822 . Assessment included weight , height , body mass index , total daily ST ( television viewing , video/computer games and Internet use ) , PA and DH using self-reported question naires . RESULTS Females were significantly more sedentary and less active than males ( P < 0.001 ) . Two-way analysis of covariance , controlling for age , showed significant ( P < 0.05 ) gender by PA and gender by ST interactions for several DH . Logistic regression analyses revealed significant associations of higher PA with a higher consumption of fruit , vegetables , milk , French fries/potato chips and energy drinks , whereas higher ST was significantly associated with a higher consumption of sugar-sweetened drinks , fast foods , cake/doughnuts and energy drinks . CONCLUSIONS Healthful dietary habits were associated mostly with  PA  , whereas sedentary behaviours , independent of PA , negatively impacted upon eating behaviours . The low PA levels and high sedentary levels of Saudi females represent a great concern . The results reported in the present study have important implication s for both youth public health policies and intervention programmes Adults are sedentary for an alarming 9 to 10 hours per day ( 1 ) . Accordingly , the popular press has coined the phrase sitting is the new smoking to describe a current epidemic of developed nations ( 24 ) . Evidence indicates that sedentary time is associated with incident cardiovascular disease , incidence of cardiovascular diseaserelated risk factors , and mortality ( 5 , 6 ) . Of note , the risk conferred by prolonged sedentariness is eliminated only by high levels of moderate- to vigorous-intensity physical activity ( MVPA ) ( about 60 to 75 min/d ) , which exceed physical activity recommendations ( 7 , 8) . As such , sedentary behavior is now believed to represent a clinical ly important aspect of a person 's physical activity profile and is no longer considered simply the extreme low end of the physical activity continuum ( 5 ) . Studies linking sedentary behavior to health outcomes have relied almost exclusively on self-reported  sedentary time  , which is subject to reporting bias and measurement error ( 9 ) . A 2015 systematic review ( 5 ) identified only 1 study ( NHANES [ National Health and Nutrition Examination Survey ] ) that examined the association between objective ly measured sedentary time and health outcomes , a study limited by a small event rate ( 10 ) . New studies using NHANES data have since been published , with longer follow-up and higher event rates ( 1115 ) . However , some of these studies have reported an association between objective ly measured sedentary time and mortality ( 11 , 14 , 15 ) , but others have not ( 12 , 13 ) . Additional cohort studies are thus needed to rectify evidence gaps . Furthermore , studies using accelerometers to objective ly measure sedentary behavior conventionally operationalize sedentary time as the total number of sedentary minutes per day . This approach ignores patterns of accumulated sedentary behavior over time . For example , accumulation of sedentary time in a few long bouts or many short bouts represents 2 distinct patterns of sedentary time accrual . Experimental studies have shown that acute periods of prolonged , uninterrupted sedentary behavior cause greater detrimental cardiometabolic effects than sedentary behavior that is periodically interrupted ( 1618 ) , suggestive that it is not just total sedentary time that is relevant to health outcomes , but also the manner in which it is accumulated . Few longitudinal studies , however , have explored the association between prolonged , uninterrupted sedentary behavior and mortality to corroborate these findings . To inform guidelines on reducing sedentary behavior ( target reductions in overall sedentary time or target interruption of prolonged sedentary bouts ) , evidence from prospect i ve studies is needed to 1 ) confirm the association between total sedentary time and mortality using objective measures , 2 ) determine whether prolonged sedentary bouts confer risk for death , and 3 ) eluci date whether the total volume of sedentary time and its pattern of accumulation individually or jointly contribute to risk for death . The purpose of this study , therefore , was to examine the association between objective ly measured sedentary time ( both total volume and accrual in prolonged bouts ) and all-cause mortality in a national cohort of U.S. middle-aged and older adults enrolled in the REGARDS ( Reasons for Geographic and Racial Differences in Stroke ) study . Methods Study Population REGARDS is a population -based study design ed to examine racial and regional disparities in stroke . It comprises 30239 white and black adults aged 45 years or older enrolled between 2003 and 2007 from across the contiguous United States ( 19 , 20 ) . Detailed design and methods for REGARDS are described elsewhere ( 21 ) . Briefly , demographic and cardiovascular risk factor data were collected by telephone interview and an in-home physical assessment on enrollment . A detailed summary of baseline measures is provided in the Supplement . Participants ( or their proxies ) were then followed for 6-month intervals to ascertain vital status . Objective measurements of sedentary behavior were collected from active REGARDS participants from 2009 to 2013 ( mean time from study enrollment , 5.7 years [ SD , 1.5 ] ; range , 1.9 to 9.5 years ) ( 22 ) . A total of 7985 participants adhered to accelerometer wear requirements ( 4 days with accelerometer wear 10 hours ) , provided follow-up data , and were available for the current analyses ( Supplement Figure 1 ) . Supplement Table 1 shows the characteristics of included versus excluded REGARDS participants . The REGARDS study protocol was approved by the institutional review boards of participating institutions . All participants provided informed consent . Supplement . Supplementary Material Accelerometer Data Collection Methods for accelerometer data collection are described elsewhere ( 22 ) . Briefly , participants were fitted with an Actical ( Philips Respironics ) accelerometer secured to their right hip using a nylon belt and were instructed to wear the device during waking hours for 7 consecutive days . The Actical had been vali date d formeasurement of physical activity and sedentary behavior and was shown to have acceptable reliability ( 2325 ) . Activity counts were summed over 1-minute epochs . Nonwear periods were defined as at least 150 consecutive minutes of 0 activity counts . This nonwear algorithm was previously vali date d against daily log sheets in REGARDS participants ( 26 ) . Measurements of 0 to 49 , 50 to 1064 , and at least 1065 counts per minute were defined as sedentary behavior , light-intensity physical activity , and MVPA , respectively , as determined in a laboratory-based calibration study ( 27 ) . A sedentary bout was defined as consecutive minutes in which the accelerometer registered fewer than 50 counts per minute . A sedentary break was defined as at least 1 minute in which 50 or more counts per minute were registered after a sedentary bout . Both sedentary bouts and breaks were exclusively continuous periods , with no interruptions or nonwear intervals allowed in the definition . Outcome Ascertainment All-cause mortality was the primary outcome , defined as any death after completion of the accelerometer protocol regardless of cause . Date s of death were confirmed through review of death certificates , medical records , and administrative data bases . Deaths through 4 September 2015 were included in the current analysis . Statistical Analysis Sedentary and physical activity variables were averaged across compliant days ( 10 hours of wear ) . Because of a high correlation between total sedentary time and wear time ( Supplement Figure 2 ) , we corrected for the influence of wear time by st and ardizing total sedentary time to 16 hours of wear time per day using the residuals obtained when regressing total sedentary time on wear time ( see Methods section of the Supplement ) ( 2830 ) . Participants were stratified into quartiles according to total sedentary time and , separately , mean sedentary bout duration ( a measure of overall prolonged , uninterrupted sedentary behavior ) . Cox proportional hazards regression modeling was used to calculate the hazard ratio ( HR ) for all-cause mortality associated with quartiles of total sedentary time ( and separately , mean sedentary bout length ) . Crude HRs were initially calculated . Subsequent HRs were calculated after adjustment for age , race , sex , region of residence , education , and season the accelerometer was worn ( model 1 ) , with further adjustment for current smoking , alcohol use , body mass index ( BMI ) , diabetes , hypertension , dyslipidemia , estimated glomerular filtration rate less than 60 mL/min/1.73 m2 , atrial fibrillation , history of coronary heart disease , and history of stroke ( model 2 ) . Models were additionally adjusted for MVPA expressed continuously ( model 3 ) . Tests for linear trend across quartiles were conducted by including the quartile for each participant as an ordinal variable in regression models . Proportional hazards assumptions were confirmed with a Kolmogorov-type supremum test ( 31 ) . The above analyses were then repeated in a fully adjusted model , testing interactions for age ( < 65 and 65 years ) , sex ( male and female ) , race ( black and white ) , BMI category ( normal weight and overweight or obese ) , and MVPA category ( < 150 min/wk and 150 min/wk ) . As a secondary analysis , we examined the continuous doseresponse relationship between each sedentary characteristic and all-cause mortality in a fully adjusted model ( model 3 ) using restricted cubic splines ( 32 ) . Cubic polynomials were fitted with the mean of each sedentary characteristic set as the reference and knots placed at the 5th , 35th , 65th , and 95th percentiles ( 33 ) . Nonlinear associations were evaluated using the likelihood ratio test . For nonlinear associations , spline models were used to describe the associations and when the association was determined to be linear , a linear model was used . Because of multicollinearity between total sedentary time and mean sedentary bout duration ( r= 0.61 ) , both variables were not included in the same model . Alternatively , to examine the individual and joint associations of total sedentary time and prolonged , uninterrupted sedentary behavior with mortality , participants were classified into 4 categories : low total sedentary time ( < 750 min/d ) and low prolonged sedentary bout time ( < 10 min/bout ) , low total sedentary time  and high prolonged sedentary bout time  ( 10 min/bout ) , high total sedentary time  ( 750 min/d ) and low prolonged sedentary bout time , and high total sedentary time and high prolonged sedentary bout time . Hazard ratios for all-cause mortality were calculated for each joint category in comparison with the lowlow group in a fully adjusted model ( model 3 ) . Thresholds for total sedentary time ( 750 min/d ) and mean sedentary bout duration ( 10 min/bout ) were selected on the basis of the restricted cubic splines and were confirmed using a method described by Contal and O'Quigley ( see Methods section of the Supplement ) ( 34 ) . To allow for the possibility that sedentary bouts BACKGROUND / OBJECTIVES Aside from the health consequences , observational studies indicate that being overweight may also negatively affect cognitive function . However , existing evidence has to a large extent not controlled for the possible confounding effect of having different lifestyles . Therefore , the objective was to examine the independent associations between weight status and lifestyle indicators with cognitive performance in 8 - 11year old Danish children . SUBJECTS/ METHODS The analyses included 828 children ( measured in 2011 - 2012 ) each having one to three measurement occasions separated by approximately 100days .  Dietary intake , physical activity , sedentary time , and sleep duration were measured using dietary records and accelerometers . The Children 's Sleep Habits Question naire was used to access sleep problems and the And ersen test was carried out to estimate cardio-respiratory fitness ( CRF ) . Weight status ( underweight , normal weight , and overweight/obese ) was defined according to body mass index and cognitive performance was assessed using the d2-test of attention , a reading test , and a math test . A linear mixed model including a number of fixed and r and om effects was used to test associations between lifestyle indicators as well as BMI category and cognitive performance . RESULTS After adjustment for demographics , socioeconomics , and multiple lifestyle indicators , normal weight children had higher cognitive test scores than overweight/obese and underweight children of up to 89 % and 48 % of expected learning within one school year ( P<0.05 ) . Daily breakfast consumption , fewer sleep problems , higher CRF , less total physical activity , more sedentary time , and less light physical activity were associated with higher cognitive performance independently of each other in at least one of the three cognitive tests ( P<0.05 ) . CONCLUSIONS Normal weight children had higher cognitive performance compared to overweight/obese as well as underweight children , independent of multiple lifestyle indicators Abstract Objective : To assess if a school based intervention was effective in reducing risk factors for obesity . Design : Group r and omised controlled trial . Setting : 10 primary schools in Leeds . Participants : 634 children aged 7 - 11 years . Intervention : Teacher training , modification of school meals , and the development of school action plans targeting the curriculum , physical education , tuck shops , and playground activities . Main outcome measures : Body mass index , diet , physical activity , and psychological state . Results : Vegetable consumption by 24 hour recall was higher in children in the intervention group than the control group ( weighted mean difference 0.3 portions/day , 95 % confidence interval 0.2 to 0.4 ) , representing a difference equivalent to 50 % of baseline consumption . Fruit consumption was lower in obese children in the intervention group ( −1.0 , −1.8 to −0.2 ) than those in the control group . The three day diary showed higher consumption of high sugar foods ( 0.8 , 0.1 to 1.6 ) ) among overweight children in the intervention group than the control group . Sedentary behaviour was higher in overweight children in the intervention group ( 0.3 , 0.0 to 0.7 ) . Global self worth was higher in obese children in the intervention group ( 0.3 , 0.3 to 0.6 ) . There was no difference in body mass index , other psychological measures , or dieting behaviour between the groups . Focus groups indicated higher levels of self reported behaviour change , underst and ing , and knowledge among children who had received the intervention . Conclusion : Although it was successful in producing changes at school level , the programme had little effect on children 's behaviour other than a modest increase in consumption of vegetables . What is already known on this topic Obesity is increasing among school children and dem and s preventive strategies R and omised controlled trials of school based primary prevention programmes have all used a prescriptive approach What this study adds Behavioural changes were disappointing with this programme based on the health promoting schools philosophy , despite changes at school level The only positive outcome was a modest increase in vegetable consumption The discrepancy between changes achieved at the individual and school level raises issues regarding the problems inherent in such Childhood obesity incidence has increased substantially and it has been argued that decreasing physical activity levels , coinciding with an increase in sedentary behaviours , are responsible . Australian guidelines were published in 2004 , recommending that children participate in a minimum of 60 min of physical activity daily and spend no more than 2h a day using electronic media for entertainment . We aim ed to compare compliance with these guidelines amongst children of differing weight status . The Childhood Injury Prevention Study ( CHIPS ) collected data from a r and omly selected sample of Brisbane primary and preschool children aged 5 - 12 years . The following data were available for 518 participants : age , gender , measured height and weight and estimated time per week from a parent-completed 7 days diary in physical activity out of school and sedentary leisure activities including television viewing and computer use . Using age st and ardised body mass index estimates , approximately 20 % of the cohort were overweight . Non-compliance with guidelines was 14.7 % for out of school physical activity participation , and 30.9 % for excess electronic media entertainment use . There was a 63 % increase in the odds of overweight status amongst children who were non-compliant with the electronic entertainment recommendations than those who were compliant ( adjusted odds ratio=1.63 ; 95 % CI=1.05 - 2.54 ) . Female gender and school level socioeconomic category were also independently associated with overweight status . Non-compliance with the minimal physical activity guideline increased the odds of being overweight by 28 % , however this difference was not statistically significant . One in seven children from the Greater Brisbane area are at risk for being insufficiently active whilst a third overuse electronic media . Given that overuse of electronic entertainment was positively associated with childhood obesity , these children should be the target of public health campaigns to promote alternative leisure time activities AIMS Australian guidelines recommend that children participate in at least one hour of physical activity every day . We aim ed to measure physical activity  participation in a r and om sample of Australian primary school children and to determine the biological , behavioural , environmental and social influences associated with insufficient daily activity . METHOD We analysed the following cross-section data from a r and omly selected sample of children ( N=518 ) aged 5 to 12 years : age , gender , socioeconmic status ( SES ) indicators , family size , home play equipment availability , transport method to school , and estimated time per week in physical and sedentary activity . Logistic regression analysis was performed to determine variables that were associated with insufficient ( < 60 minutes ) daily activity . RESULTS Seventy-six children ( 15 % of the cohort ) failed to meet the minimum activity recommendations of 60 minutes of daily activity . These children were significantly less likely to walk or cycle to school ( adjusted odds ratio ( OR ) 0.43 ; 95 % CI=0.24 - 0.77 ) or participate in organised sports or activity ( OR 0.42 ; 95 % CI=0.28 - 0.64 ) and were more likely to spend in excess of 2 hours a day watching television of using a computer for entertainment ( OR 2.10 ( 1.16 - 3.78 ) . Age , gender , SES and family size were not significantly associated with insufficient activity . CONCLUSION There exists a significant proportion of the paediatric population who are insufficiently active . Interventions to encourage increased activity  in this sub-group may be successful if they seek to alter sedentary behaviour ( namely television use ) and method of transportation to and from school Background Worldwide in 2000 , 10 % of children aged five to 17 years were reported as being overweight with an additional 2‐3 % being obese . Overweight and obesity in childhood can adversely impact on both physical and psychological health . The rise in the prevalence of childhood obesity is a complex issue but widely recognised contributors include increased energy intake , decreased levels of physical activity and greater time spent in sedentary pursuits . A large number of environmental and cultural factors have also been identified as contributing to the problem . Evidence to support an optimal approach to treating childhood obesity is limited with many studies showing only modest results at best in the long‐term . However , the importance of family‐based treatment that combines diet , physical activity and behavioral components has been acknowledged in a recent Cochrane Systematic Review . It has also been suggested that interventions offered in the community setting may help overcome barriers to participation , by making programs more accessible and allowing the targeting of specific sub‐groups of the population . Objectives The objective of this review was to identify the effectiveness of parent‐centred interventions implemented in the community setting in modifying eating and physical activity behaviors or weight‐related outcomes of children . Inclusion criteria Types of participants This review considered studies that included free‐living children of pre‐school , primary and secondary school age and /or their parents/guardians aged > 18 years . Types of intervention(s)/phenomena of interest Intervention programs were required to have a parental component , to target eating and /or exercise behaviors for the prevention or treatment of obesity , and child weight status reported . Types of studies All intervention studies were included in the review including : r and omized controlled trials ( RCTs ) ; non‐r and omized controlled trials , longitudinal studies , cohort ( both retrospective and prospect i ve ) , case control and time series studies which had been conducted in a community setting . Types of outcomes This review considered studies that included overweight/obesity related outcomes , eating behavior outcomes , physical activity behaviour outcomes , and sedentary behavior outcomes and constructs . Search strategy A literature search of community‐based parent‐centred intervention studies to promote nutrition and physical activity for the prevention and treatment and of childhood overweight and obesity was performed in eight electronic data bases dating from 1975 to April 2009 . Method ological quality Studies were critically appraised for method ological quality using st and ardized tools . Data collection Data was extracted by one review er using a st and ardized data extraction form developed by the research ers and checked for accuracy and consistency by a second review er . Data synthesis Data in relation to setting , methodology , intervention components and effect on weight , dietary intake and physical activity was extracted , and described in a narrative synthesis . Where possible a meta‐ analysis was undertaken . Results Of the home‐based interventions , five of nine studies reported statistically significant changes in anthropometric outcomes post intervention . Of the 10 studies in the before and after school care setting , seven reported a significant decrease in a weight‐related outcome post intervention , with only one reporting an increase . Conclusions Results from the review support the after‐school setting as the most promising for community intervention setting for targeting parents as agents of change within child obesity prevention and treatment programs . Implication s for practice At this stage , interventions to support parents should target the after‐school environment as opposed to being conducted in the home , summer camps , leisure centers or churches . Targeting a decrease in energy intake and sweetened beverages in parallel with increasing number of daily steps and decreasing screen time use . Implication s for research Future studies of high quality are needed across the full range of community setting s. Given that currently most of the higher quality RCTs and the studies showing positive impacts of weight change are in the after‐school setting , further studies in this area using similar method ologies to those already published will facilitate future meta‐analyses in this area Background Excessive time spent in sedentary behaviours ( sitting or lying with low energy expenditure ) is associated with an increased risk for type 2 diabetes , cardiovascular disease and some cancers . Desk-based office workers typically accumulate high amounts of daily sitting time , often in prolonged unbroken bouts . The St and Up Victoria study aims to determine whether a 3-month multi-component intervention in the office setting reduces workplace sitting , particularly prolonged , unbroken sitting time , and results in improvements in cardio-metabolic biomarkers and work-related outcomes , compared to usual practice . Methods / Design A two-arm cluster-r and omized controlled trial ( RCT ) , with worksites as the unit of r and omization , will be conducted in 16 worksites located in Victoria , Australia . Work units from one organisation ( Department of Human Services , Australian Government ) will be allocated to either the multi-component intervention ( organisational , environmental [ height-adjustable workstations ] , and individual behavioural strategies ) or to a usual practice control group . The recruitment target is 160 participants ( office-based workers aged 18–65 years and working at least 0.6 full time equivalent ) per arm . At each assessment ( 0- [ baseline ] , 3- [ post intervention ] , and 12-months [ follow-up ] ) , objective measurement via the activPAL3 activity monitor will be used to assess workplace : sitting time ( primary outcome ) ; prolonged sitting time ( sitting time accrued in bouts of ≥30 minutes ) ; st and ing time ; sit-to-st and transitions ; and , moving time . Additional outcomes assessed will include : non-workplace activity ; cardio-metabolic biomarkers and health indicators ( including fasting glucose , lipids and insulin ; anthropometric measures ; blood pressure ; and , musculoskeletal symptoms ) ; and , work-related outcomes ( presenteeism , absenteeism , productivity , work performance ) . Incremental cost-effectiveness and identification of both workplace and individual-level mediators and moderators of change will also be evaluated . Discussion St and Up Victoria will be the first cluster- RCT to evaluate the effectiveness of a multi-component intervention aim ed at reducing prolonged workplace sitting in office workers . Strengths include the objective measurement of activity and assessment of the intervention on markers of cardio-metabolic health . Health- and work-related benefits , as well as the cost-effectiveness of the intervention , will help to inform future occupational practice .Trial registration Aims This study assessed the efficacy of a school-based healthy lifestyle intervention ( Sport for LIFE ) for increasing physical activity , decreasing sedentary behaviour , reducing screen time behaviour , encouraging healthy attitudes and behaviour to nutrition , and reducing body mass index ( BMI ) in 8–9-year-old primary school children from lower socioeconomic background s in Northern Irel and . Methods A non-r and omised controlled trial of 416 children from 24 schools took part . Schools were r and omly assigned to one of two groups , an intervention or control group with 12 schools in each group . The intervention group received a 12-week school-based programme based on social cognitive theory . At baseline and follow-up , groups completed question naires assessing physical activity , screen time behaviour and dietary patterns . On each occasion anthropometric assessment  s of height and weight were taken . Physical activity and sedentary behaviour were measured by accelerometry . Results Significant effects were observed for vigorous , moderate and light activity for the intervention group at follow-up . Sedentary behaviour was significantly reduced for the intervention group but not for the control group . No significant effects of the intervention on BMI , screen time behaviour or attitudes to nutrition , with the exception of non-core foods , were shown . Conclusions The programme was effective in increasing physical activity and reducing sedentary behaviour , however no significant changes in screen time behaviour and attitude to nutrition , with the exception of non-core foods , were observed . Future research ideas are offered for tackling low levels of physical activity in children
There is a large body of evidence from all study design s which suggests that decreasing any type of sedentary time is associated with lower health risk in youth aged 5 - 17 years .
In particular , the evidence suggests that daily TV viewing in excess of 2 hours is associated with reduced physical and psychosocial health , and that lowering sedentary time leads to reductions in BMI
Accumulating evidence suggests that , independent of physical activity levels , sedentary behaviours are associated with increased risk of cardio-metabolic disease , all-cause mortality , and a variety of physiological and psychological problems .
Therefore , the purpose of this systematic review is to determine the relationship between sedentary behaviour and health indicators in school-aged children and youth aged 5 - 17 years .