A behaviour change intervention to reduce sedentary time in people with chronic obstructive pulmonary disease: protocol for a randomised controlled trial. Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults Exercise and cognitive function: a randomized controlled trial examining acute exercise and free-living physical activity and sedentary effects. Participatory Workplace Interventions Can Reduce Sedentary Time for Office Workers—A Randomised Controlled Trial Accelerometer-measured dose-response for physical activity, sedentary time, and mortality in US adults. Physical activity, sedentary behavior and total wellness changes among sedentary adults: a 4-week randomized controlled trial Calibration and validation of the ActiGraph GT3X+ in 2-3 year olds. Objectively Measured Sedentary Time May Predict Insulin Resistance Independent of Moderate- and Vigorous-Intensity Physical Activity Research priorities for child and adolescent physical activity and sedentary behaviours: an international perspective using a twin-panel Delphi procedure Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers The Malaysian Childhood Obesity Treatment Trial (MASCOT). Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults 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 Long-chain n-3 PUFA supplementation decreases physical activity during class time in iron-deficient South African school children. Children, parents, and pets exercising together (CPET) randomised controlled trial: study rationale, design, and methods
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 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 OBJECTIVE To simultaneously examine the effects of acute exercise intensity and free-living physical activity and sedentary behavior on cognitive function in young , healthy adults . PATIENTS AND METHODS Using a counterbalanced , crossover , r and omized controlled design , 87 young adults ( mean age , 21.4 years ) completed various cognitive assessment s with and without an acute bout of exercise preceding the assessment . Participants were r and omized into 1 of 4 groups to complete a 30-minute bout of acute exercise : control ( no exercise ) , light intensity ( 40%-50 % of predicted maximum heart rate [ HR(max ) ] ) , moderate intensity ( 51%-70 % of predicted HR(max ) ) , or vigorous intensity ( 71%-85 % of predicted HR(max ) ) . Subjectively and objective ly determined ( accelerometry ) physical activity and sedentary behavior were assessed to examine the association between these free-living behaviors and cognitive function . The study duration was August 26 , 2013 , to September 11 , 2014 . RESULTS Concentration-related cognition ( mean ± SD Feature Match test score ) was significantly higher after a 30-minute acute bout of moderate-intensity exercise ( 145.1±26.9 ) compared with cognitive assessment without exercise ( 121.3±19.2 ; P=.004 ) . Furthermore , question naire-determined sedentary behavior was inversely associated with visual attention and task switching ( Trail Making Test A score ) ( β=-0.23 ; P=.04 ) . Last , estimated cardiorespiratory fitness ( volume of maximum oxygen consumption ) was positively associated with reasoning-related cognitive function ( Odd One Out test score ) ( β=0.49 ; P=.05 ) ; when adding metabolic equivalent of task minutes per week to this model , the results were not significant ( β=0.47 ; P=.07 ) . CONCLUSION These findings provide some support for acute moderate-intensity exercise , sedentary behavior , and cardiorespiratory fitness being associated with executive functioning-related cognitive function in young , healthy adults Background Occupational sedentary behaviour is an important contributor to overall sedentary risk . There is limited evidence for effective workplace interventions to reduce occupational sedentary time and increase light activity during work hours . The purpose of the study was to determine if participatory workplace interventions could reduce total sedentary time , sustained sedentary time ( bouts > 30 minutes ) , increase the frequency of breaks in sedentary time and promote light intensity activity and moderate/vigorous activity ( MVPA ) during work hours . Methods A r and omised controlled trial ( ANZCTR number : ACTN12612000743864 ) was conducted using clerical , call centre and data processing workers ( n = 62 , aged 25–59 years ) in 3 large government organisations in Perth , Australia . Three groups developed interventions with a participatory approach : ‘ Active office ’ ( n = 19 ) , ‘ Active Workstation ’ and promotion of incidental office activity ; ‘ Traditional physical activity ’ ( n = 14 ) , pedometer challenge to increase activity between productive work time and ‘ Office ergonomics ’ ( n = 29 ) , computer workstation design and breaking up computer tasks . Accelerometer ( ActiGraph GT3X , 7 days ) determined sedentary time , sustained sedentary time , breaks in sedentary time , light intensity activity and MVPA on work days and during work hours were measured before and following a 12 week intervention period . Results For all participants there was a significant reduction in sedentary time on work days ( −1.6 % , p = 0.006 ) and during work hours ( −1.7 % , p = 0.014 ) and a significant increase in number of breaks/sedentary hour on work days ( 0.64 , p = 0.005 ) and during work hours ( 0.72 , p = 0.015 ) ; there was a concurrent significant increase in light activity during work hours ( 1.5 % , p = 0.012 ) and MVPA on work days ( 0.6 % , p = 0.012 ) . Conclusions This study explored novel ways to modify work practice s to reduce occupational sedentary behaviour . Participatory workplace interventions can reduce sedentary time , increase the frequency of breaks and improve light activity and MVPA of office workers by using a variety of interventions . Trial Registration Australian New Zeal and Clinical Trials Registry ACTN12612000743864 BACKGROUND Moderate-to-vigorous-intensity physical activity is recommended to maintain and improve health , but the mortality benefits of light activity and risk for sedentary time remain uncertain . OBJECTIVES Using accelerometer-based measures , we 1 ) described the mortality dose-response for sedentary time and light- and moderate-to-vigorous-intensity activity using restricted cubic splines , and 2 ) estimated the mortality benefits associated with replacing sedentary time with physical activity , accounting for total activity . DESIGN US adults ( n = 4840 ) from NHANES ( 2003 - 2006 ) wore an accelerometer for ≤7 d and were followed prospect ively for mortality . Proportional hazards models were used to estimate adjusted HRs and 95 % CIs for mortality associations with time spent sedentary and in light- and moderate-to-vigorous-intensity physical activity . Splines were used to graphically present behavior-mortality relation . Isotemporal models estimated replacement associations for sedentary time , and separate models were fit for low- ( < 5.8 h total activity/d ) and high-active participants to account for nonlinear associations . RESULTS Over a mean of 6.6 y , 700 deaths occurred . Compared with less-sedentary adults ( 6 sedentary h/d ) , those who spent 10 sedentary h/d had 29 % greater risk ( HR : 1.29 ; 95 % CI : 1.1 , 1.5 ) . Compared with those who did less light activity ( 3 h/d ) , those who did 5 h of light activity/d had 23 % lower risk ( HR : 0.77 ; 95 % CI : 0.6 , 1.0 ) . There was no association with mortality for sedentary time or light or moderate-to-vigorous activity in highly active adults . In less-active adults , replacing 1 h of sedentary time with either light- or moderate-to-vigorous-intensity activity was associated with 18 % and 42 % lower mortality , respectively . CONCLUSIONS Health promotion efforts for physical activity have mostly focused on moderate-to-vigorous activity . However , our findings derived from accelerometer-based measurements suggest that increasing light-intensity activity and reducing sedentary time are also important , particularly for inactive adults Background The construct of total wellness includes a holistic approach to the body , mind and spirit components of life . While the health benefits of reducing sedentary behavior and increasing physical activity are well documented , little is known about the influence on total wellness of an internet-based physical activity monitor design ed to help people to achieve higher physical activity levels . Purpose The purpose of this four-week , personal activity monitor-based intervention program was to reduce sedentary behavior and increase physical activity levels in daily living for sedentary adults and to determine if these changes would also be associated with improvement in total wellness . Methods Twenty-two men and 11 women ( 27 years ± 4.0 ) were r and omly assigned to either an intervention ( n = 18 ) or control group ( n = 15 ) . The intervention group interacted with an online personal activity monitor ( Gruve Solution ™ ) design ed to reduce sedentary time  and increase physical activity during activities of daily living . The control group did not interact with the monitor , as they were asked to follow their normal daily physical activities and sedentary behavior routines . The Wellness Evaluation of Lifestyle ( WEL ) inventory was used to assess total wellness . Sedentary time , light , walking , moderate and vigorous intensity physical activities were assessed for both intervention and control groups at baseline and at week-4 by the 7-day Sedentary and Light Intensity Physical Activity Log ( 7-day SLIPA Log ) and the International Physical Activity Question naire ( IPAQ ) . Results Significant increases in pre-post total wellness scores ( from 64 % ± 5.7 to 75 % ± 8.5 ) ( t ( 17 ) = -6.5 , p < 0.001 ) were observed in the intervention group by the end of week four . Intervention participants decreased their sedentary time ( 21 % , 2.3 hours/day ) and increased their light ( 36.7 % , 2.5 hours/day ) , walking ( 65 % , 1057 MET-min/week ) , moderate ( 67 % , 455 MET-min/week ) and vigorous intensity ( 60 % , 442 MET-min/week ) physical activity ( all p < 0.001 ) . No significant differences for total wellness were observed between the groups at baseline and no pre-post significant differences were observed for any outcome variable in the control group . Conclusion Total wellness is improved when sedentary , but sufficiently physically active adults , reduce sedentary time and increase physical activity levels ( i.e. light , waking , moderate and vigorous ) OBJECTIVES To calibrate and vali date the ActiGraph GT3X+ to measure sedentary behaviour and physical activity in 2 - 3 year olds , using 5-s epochs ; and to compare the predictive validity of the result ing cut-points with that of NHANES ' , Trost 's , and Pate 's 15-s cut-points . DESIGN Cross-sectional study . METHODS Eighteen children ( 2.86 ± 0.60 years ) wore an ActiGraph GT3X+ during video-recorded semi-structured calibration activity sessions . Activity was coded following Children 's Activity Rating Scale . Receiver Operating Characteristic analysis was used to derive Axis1 and vector magnitude cut-points for sedentary behaviour and moderate-to-vigorous physical activity at 5-s epochs . Agreement with Children 's Activity Rating Scale was assessed with Cohen 's kappa , Lin 's concordance , and Bl and -Altman plots . Predictive validity of all cut-points was assessed in an independent sample of 20 children ( 2.99 ± 0.48 years ) video-recorded during free-play , using the same procedures as the calibration phase . RESULTS During calibration , vector magnitude cut-points ( sedentary behaviour ≤ 96.12 counts ; moderate-to-vigorous physical activity ≥ 361.94 counts ) showed slightly better classification agreement with Children 's Activity Rating Scale than Axis1 cut-points ( sedentary behaviour ≤ 5 counts ; moderate-to-vigorous physical activity ≥ 165 counts ) , but the latter showed the lowest bias in estimated sedentary behaviour and moderate-to-vigorous physical activity time . In the validation sample , 5-s Axis1 cut-points showed the best predictive validity and lowest mean differences of all cut-points between predicted and observed sedentary behaviour ( -2.31 % ) , light physical activity ( -24.40 % ) , and total physical activity time ( -0.95 % ) . Moderate-to-vigorous physical activity time was significantly overestimated by all cut-points ( 128.33 - 184.17 % ) . CONCLUSIONS Because moderate-to-vigorous physical activity was highly overestimated , using only the 5-s Axis1 sedentary behaviour cut-point to distinguish sedentary behaviour from total physical activity is advised . The high accuracy indicates that these cut-points are useful for epidemiological studies involving the sedentary behaviour and physical activity of 2 - 3 year olds OBJECTIVE To examine the prospect i ve association between objective ly measured time spent sedentary and insulin resistance and whether this association is independent of moderate- and vigorous-intensity physical activity ( MVPA ) and other relevant confounders . RESEARCH DESIGN AND METHODS This was a population -based study ( Medical Research Council Ely study ) in 376 middle-aged adults ( 166 men ; 210 women ) over 5.6 years of follow-up .  Physical activity and sedentary time were measured objective ly by individually calibrated minute-by-minute heart rate monitoring at both baseline and follow-up .  Sedentary time  was calculated as the heart rate observations ( in minutes ) below an individually predetermined threshold ( flex heart rate ) and expressed as a percentage of total monitored time during waking hours over 4 days . The percentage of time spent above 1.75 × resting heart rate represented MVPA . Fasting plasma insulin was used as a surrogate measure of insulin resistance . RESULTS Time spent sedentary  at baseline was significantly and positively associated with log fasting insulin at follow-up ( β = 0.003 , 95 % CI 0.0006–0.006 , P = 0.015 ) independent of baseline age , sex , fat mass , fasting insulin , smoking status , and follow-up time . After further adjustment for MVPA , this association was somewhat strengthened ( β = 0.004 , 95 % CI 0.0009–0.006 , P = 0.009 ) . CONCLUSIONS Time spent sedentary predicts higher levels of fasting insulin independent of the amount of time spent at moderate- and vigorous-intensity activity levels . This highlights the importance of reducing sedentary time in order to improve metabolic health , possibly in addition to the benefits associated with a physically active lifestyle Background The quantity and quality of studies in child and adolescent physical activity and sedentary behaviour have rapidly increased , but research directions are often pursued in a reactive and uncoordinated manner . Aim To arrive at an international consensus on research priorities in the area of child and adolescent physical activity and sedentary behaviour . Methods Two independent panels , each consisting of 12 experts , undertook three rounds of a Delphi methodology . The Delphi methodology required experts to anonymously answer questions put forward by the research ers with feedback provided between each round . Results The primary outcome of the study was a ranked set of 29 research priorities that aim ed to be applicable for the next 10 years . The top three ranked priorities were : developing effective and sustainable interventions to increase children ’s physical activity long-term ; policy and /or environmental change and their influence on children ’s physical activity and sedentary behaviour ; and prospect i ve , longitudinal studies of the independent effects of physical activity and sedentary behaviour on health . Conclusions These research priorities can help to guide decisions on future research directions 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 INTRODUCTION The present study describes a r and omised controlled trial ( RCT ) based on a novel , generalisable intervention for childhood obesity , comparing the intervention with a no-treatment control group . METHOD The Malaysian Childhood Obesity Treatment Trial ( MASCOT ) was a single-blind RCT of a dietetic treatment for childhood obesity in children of primary school age ( 7 to 11 years old ) in Kuala Lumpur , Malaysia . The MASCOT comprising eight sessions , of an 8-hour family-centred group treatment programme is described , based on behavioural change techniques . The study sample was characterised by BMI z-score , health related quality of life reported by participants and their parents ( PedsQL question naire ) , objective ly measured habitual physical activity and sedentary behaviour ( Actigraph accelerometry ) RESULTS The MASCOT sample of 107 children was characterised by a low quality of life , mean total score on PedsQL 67.7 ( 4.5 ) as reported by the children , and 66.0 ( 16.4 ) as reported by their parents . The children spent , on average , 89 % of their waking day on sedentary activity , and 1 % of the day in moderate-vigorous intensity physical activity , equivalent to only around 8 minutes/day . CONCLUSION Obese children in the MASCOT study had an impaired quality of life , high levels of sedentary behaviour and very low levels of physical activity Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing . To date , accelerometers using cut-off point models are most preferred for this , however , machine learning seems a highly promising future alternative . Hence , the current study compared between cut-off point and machine learning algorithms , for optimal quantification of sedentary behaviour and physical activity intensities in the elderly . Thus , in a heterogeneous sample of forty participants ( aged ≥60 years , 50 % female ) energy expenditure during laboratory-based activities ( ranging from sedentary behaviour through to moderate-to-vigorous physical activity ) was estimated by indirect calorimetry , whilst wearing triaxial thigh-mounted accelerometers . Three cut-off point algorithms and a R and om Forest machine learning model were developed and cross-vali date d using the collected data . Detailed analyses were performed to check algorithm robustness , and examine and benchmark both overall and participant-specific balanced accuracies . This revealed that the four models can at least be used to confidently monitor sedentary behaviour and moderate-to-vigorous physical activity . Nevertheless , the machine learning algorithm outperformed the cut-off point models by being robust for all individual ’s physiological and non-physiological characteristics and showing more performance of an acceptable level over the whole range of physical activity intensities . Therefore , we propose that R and om Forest machine learning may be optimal for objective assessment of sedentary behaviour and physical activity in older adults using thigh-mounted triaxial accelerometry 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 Both Fe deficiency and poor n-3 fatty acid status have been associated with behavioural changes in children . In the present study , we investigated the effects of Fe and DHA+EPA supplementation , alone or in combination , on physical activity during school days and on teacher-rated behaviour in healthy Fe-deficient school children . In a 2 × 2 factorial design , children ( n 98 , 6 - 11 years ) were r and omly assigned to receive ( 1 ) Fe ( 50 mg ) plus DHA ( 420 mg)+EPA ( 80 mg ) , ( 2 ) Fe plus placebo , ( 3 ) placebo plus DHA+EPA or ( 4 ) placebo plus placebo as oral supplements ( 4 d/week ) for 8.5 months . Physical activity was measured during four school days at baseline and endpoint using accelerometers , and data were stratified into morning class time ( 08.00 - 10.29 hours ) , break time ( 10.30 - 11.00 hours ) and after-break class time ( 11.01 - 12.00 hours ) for analysis . Classroom behaviour was assessed at endpoint using Conners ' Teacher Rating Scales . DHA+EPA supplementation decreased physical activity counts during morning class time , increased sedentary physical activity , and decreased light- and moderate-intensity physical activities . Consistently , DHA+EPA supplementation increased sedentary physical activity and decreased light-intensity physical activity during after-break class time . Even though there were no treatment effects found on teacher-rated behaviour , lower physical activity during morning class time was associated with lower levels of teacher-rated hyperactivity and oppositional behaviour at endpoint . Despite a positive association between Fe status and physical activity during break time at baseline , Fe supplementation did not affect physical activity during break time and class time . Our findings suggest that DHA+EPA supplementation may decrease physical activity levels during class time , and further indicate that accelerometry might be a useful tool to assess classroom behaviour in healthy children Background Objective ly measured physical activity is low in British children , and declines as childhood progresses . Observational studies suggest that dog-walking might be a useful approach to physical activity promotion in children and adults , but there are no published public health interventions based on dog-walking with children . The Children , Parents , and Pets Exercising Together Study aims to develop and evaluate a theory driven , generalisable , family-based , dog walking intervention for 9 - 11 year olds . Methods / design The Children , Parents , and Pets Exercising Together Study is an exploratory , assessor-blinded , r and omised controlled trial as defined in the UK MRC Framework on the development and evaluation of complex interventions in public health . The trial will follow CONSORT guidance . Approximately 40 dog-owning families will be allocated r and omly in a ratio of 1.5:1 to receive a simple behavioural intervention lasting for 10 weeks or to a ' waiting list ' control group . The primary outcome is change in objective ly measured child physical activity using Actigraph accelerometry . Secondary outcomes in the child , included in part to shape a future more definitive r and omised controlled trial , are : total time spent sedentary and patterning of sedentary behaviour ( Actigraph accelerometry ) ; body composition and bone health from dual energy x-ray absorptiometry ; body weight , height and BMI ; and finally , health-related quality of life using the PedsQL . Secondary outcomes in parents and dogs are : changes in body weight ; changes in Actigraph accelerometry measured physical activity and sedentary behaviour . Process evaluation will consist of assessment of simultaneous child , parent , and dog accelerometry data and brief interviews with participating families . Discussion The Children , Parents , and Pets Exercising Together trial should be the first r and omised controlled study to establish and evaluate an intervention aim ed at dog-based physical activity promotion in families . It should advance our underst and ing of whether and how to use  pet dogs to promote physical activity and /or to reduce sedentary behaviour in children and adults . The trial is intended to lead to a subsequent more definitive r and omised controlled trial , and the work should inform future dog-based public health interventions such as secondary prevention interventions in children or adults . Trial registration numberIS RCT
Based on 88 eligible observational studies , level of evidence grading and quantitative meta-analyses indicated that there is limited available evidence that the total volume or patterns of sedentary behaviour are associated with health in children and adolescents when accounting for moderate-intensity to vigorous-intensity physical activity or focusing on studies with low risk of bias .
Quality evidence from studies with robust design s and methods , objective measures of sitting , examining associations for various health outcomes , is needed to better underst and if the overall volume or patterns of sedentary behaviour are independent determinants of health in children and adolescents
Sedentary behaviour has emerged as a unique determinant of health in adults .
Studies in children and adolescents have been less consistent .
We review ed the evidence to determine if the total volume and patterns ( i.e. breaks and bouts ) of objective ly measured sedentary  behaviour  were associated with adverse health outcomes in young people , independent of moderate-intensity to vigorous-intensity physical activity .