Accelerometer-measured sedentary time and physical activity-A 15 year follow-up of mortality in a Swedish population-based cohort. A Novel Approach to Characterize Physical Activity Patterns in Preschool-Aged Children Using Ecological Momentary Assessment to Understand Where and With Whom Adults’ Physical and Sedentary Activity Occur The effect of a classroom activity break on physical activity levels and adiposity in primary school children. Investigating children's physical activity and sedentary behavior using ecological momentary assessment with mobile phones. Development of an Accelerometer-Linked Online Intervention System to Promote Physical Activity in Adolescents Effectiveness of a 12-month randomized clinical trial to increase physical activity in multiethnic postpartum women: results from Hawaii's Nā Mikimiki Project. MVPA Is Associated with Lower Weight Gain in 8–10 Year Old Children: A Prospective Study with 1 Year Follow-Up Personal and social-environmental correlates of objectively measured physical activity in Norwegian pre-adolescent children. Reducing Sedentary Behavior Versus Increasing Moderate-to-Vigorous Intensity Physical Activity in Older Adults Physical activity, sedentary behavior, and adiposity in English children. Objectively Measured Moderate- and Vigorous-Intensity Physical Activity but Not Sedentary Time Predicts Insulin Resistance in High-Risk Individuals Organizing “Play Streets” during school vacations can increase physical activity and decrease sedentary time in children Secular and longitudinal physical activity changes in population‐based samples of children and adolescents Cross-sectional and prospective associations between moderate to vigorous physical activity and sedentary time with adiposity in children Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning
OBJECTIVES To investigate the associations of objective ly assessed sedentary time , light intensity physical activity ( PA ) , moderate to vigorous intensity PA ( MVPA ) , and total PA with all-cause mortality and mortality from cardiovascular disease ( CVD ) or cancer in a Swedish population -based cohort with 15 years follow-up time . DESIGN Longitudinal prospect i ve cohort study . METHODS Data from 851 persons ( 56 % women ) ≥35 years at baseline were included . Primary exposure variables were  time ( min/day ) spent sedentary , in light intensity PA and in MVPA , and total counts from an Actigraph 7164 accelerometer . Data on all-cause mortality and mortality from CVD or cancer were obtained from Swedish registers . Cox proportional hazards models estimated hazard ratios ( HR ) of mortality with 95 % confidence intervals ( CI ) . RESULTS Compared with the least sedentary participants , those in the most sedentary tertile had an increased risk of all-cause mortality , HR : 2.7 ( 1.4 , 5.3 ) , CVD mortality , HR : 5.5 ( 1.4 , 21.2 ) and cancer mortality , HR : 4.3 ( 1.2 , 16.0 ) . For all-cause mortality , those in the highest light intensity PA tertile had a HR 0.34 ( 0.17 , 0.67 ) compared with the lowest tertile . A similar pattern was found for CVD and cancer mortality . More time spent in MVPA was associated with the largest risk reduction for CVD mortality , with an almost 90 % lower risk in the tertile with the most time in MVPA . CONCLUSIONS This study confirms a strong inverse relationship between MVPA and mortality , and adds new insight for the underst and ing of the associations between sedentary time  and light intensity PA  and mortality Objective Routine moderate-to-vigorous physical activity ( MVPA ) is associated with better health outcomes ; the purpose of this work was to evaluate healthy preschooler physical activity patterns with objective measurement . Methods and Procedures An objective prospect i ve study of fifty normally-developing children 3–5 years old who were ≥50th and < 95th BMI percentile and enrolled in a family-based healthy lifestyle study in 2011–2012 . Participants wore a tri-axial accelerometer for 7 continuous days . Outcome measures consisted of wear time examining four common MVPA patterns : isolated spurt ( IS ) , isolated sustained activity ( ISA ) , clustered spurt ( CS ) , and clustered sustained activity ( CSA ) . Results Participants were 4.3 years , 56 % female , 52 % African-American , and 26 % overweight . Forty-five children met wear time criteria . On average , children spent 14.5 % of wake-wear time in MVPA , requiring 11.3 hours to complete 90 % of their daily MVPA . Children spent the majority of MVPA in CS ( 62.1 % , followed by CSA ( 20.1 % ) . Remaining MVPA was spent in IS ( 15.5 % ) and ISA ( 2.3 % ) . Conclusion It takes most of the waking day for preschoolers to attain their PA . They engage in short spurts of small duration , in four common MVPA patterns . Utilizing this method could better characterize preschooler physical activity needs in practice and policy guidelines Purpose This study used Ecological Momentary Assessment ( EMA ) , a real-time self-report strategy , to describe the physical and social context s of adults ’ physical activity and sedentary activity during their everyday lives and to determine whether these patterns and relationships differ for men and women . Methods Data from 114 adults were collected through mobile phones across 4 days . Eight electronic EMA surveys were r and omly prompted each day asking about current activities ( e.g. , physical or sedentary activity ) , physical and social context s , and perceived outdoor environmental features ( e.g. , greenness/vegetation , safety , and traffic ) . All participants also wore accelerometers during this period to objective ly measure moderate-to-vigorous physical activity ( MVPA ) and sedentary activity . Results Home was the most common physical context for EMA-reported physical and sedentary activity . Most of these activities occurred when participants were alone . When alone , the most commonly EMA-reported physical activity and sedentary activity was walking and reading/using computer , respectively . When in outdoor home locations ( e.g. , yard and driveway ) women demonstrated higher levels of MVPA , whereas men demonstrated higher levels of MVPA when in outdoor park setting s ( ps < .05 ) . Men but not women demonstrated higher levels of MVPA in setting s with a greater degree of perceived greenness and vegetation ( p < .05 ) . Conclusions The current study shows how EMA via mobile phones and accelerometers can be combined to offer an innovative approach to assess the context s of adults ’ daily physical and sedentary activity . Future studies could consider utilizing this method in more representative sample s to gather context -specific information to inform the development of physical activity interventions AIM Despite recognition that regular physical activity is essential for good health , many children do not accumulate sufficient daily physical activity . The aim of this study was to examine the effect of a classroom-based activity break on accelerometer-determined moderate-to-vigorous intensity physical activity ( MVPA ) and adiposity in primary school children . METHODS One hundred twenty children from seven primary schools in Northern Irel and participated in the study . In each school , one class of children was r and omly assigned to an intervention group and another class to a control group . Teachers of the intervention classes led a 5-min activity break three times per day for 12 weeks .  Accelerometer-determined MVPA , height , weight and four skinfolds  were measured at baseline and post-intervention . RESULTS Compared with the control group , the intervention group significantly increased weekday MVPA ( + 9.5 min ) from baseline to post-intervention . There were no significant changes in BMI ; however , an increase in sum-of-skinfolds of the intervention group was observed . CONCLUSIONS Classroom-based activity breaks led by the teacher are successful in increasing  children 's  physical activity levels . The programme shows a positive step in improving overall physical activity levels and contributing to the goal of 60 min daily MVPA The risk of obesity during childhood can be significantly reduced through increased physical activity and decreased sedentary behavior . Recent technological advances have created opportunities for the real-time measurement of these behaviors . Mobile phones are ubiquitous and easy to use , and thus have the capacity to collect data from large numbers of people . The present study tested the feasibility , acceptability , and validity of an electronic ecological momentary assessment ( EMA ) protocol using electronic surveys administered on the display screen of mobile phones to assess children 's physical activity and sedentary behaviors .  A total of 121 children ( ages 9 - 13 , 51 % male , 38 % at risk for overweight/overweight ) participated in EMA monitoring from Friday afternoon to Monday evening during children 's nonschool time , with 3 - 7 surveys/day . Items assessed current activity ( e.g. , watching TV/movies , playing video games , active play/sports/exercising ) . Children simultaneously wore an Actigraph GT2 M accelerometer . EMA survey responses were time-matched to total step counts and minutes of moderate-to-vigorous physical activity ( MVPA ) occurring in the 30 min before each EMA survey prompt . No significant differences between answered and unanswered EMA surveys were found for total steps or MVPA . Step counts and the likelihood of 5 + min of MVPA were significantly higher during EMA-reported physical activity ( active play/sports/exercising ) vs. sedentary behaviors ( reading/computer/homework , watching TV/movies , playing video games , riding in a car ) ( P < 0.001 ) . Findings generally support the acceptability and validity of a 4-day EMA protocol using mobile phones to measure physical activity and sedentary behavior in children during leisure time Most adolescents do not achieve the recommended levels of moderate-to-vigorous physical activity ( MVPA ) , placing them at increased risk for a diverse array of chronic diseases in adulthood . There is a great need for scalable and effective interventions that can increase MVPA in adolescents . Here we report the results of a measurement validation study and a preliminary proof-of-concept experiment testing the impact of Zamzee , an accelerometer-linked online intervention system that combines proximal performance feedback and incentive motivation features to promote MVPA . In a calibration study that parametrically varied levels of physical activity in 31 12 - 14 year-old children , the Zamzee activity meter was shown to provide a valid measure of MVPA ( sensitivity in detecting MVPA = 85.9 % , specificity = 97.5 % , and r = .94 correspondence with the benchmark RT3 accelerometer system ; all p < .0001 ) . In a subsequent r and omized controlled multi-site experiment involving 182 middle school-aged children assessed for MVPA over 6 wks , intent-to-treat analyses found that those who received access to the Zamzee intervention had average MVPA levels 54 % greater than those of a passive control group ( p < 0.0001 ) and 68 % greater than those of an active control group that received access to a commercially available active videogame ( p < .0001 ) . Zamzee ’s effects on MVPA did not diminish significantly over the course of the 6-wk study period , and were statistically significant in both females and males , and in normal- vs. high- BMI subgroups . These results provide promising initial indications that combining the Zamzee activity meter with online proximal performance feedback and incentive motivation features can positively impact MVPA levels in adolescents OBJECTIVE Few postpartum ethnic minority women perform leisure-time moderate-to-vigorous physical activity ( MVPA ) . The study tested the effectiveness of a 12-month tailored intervention to increase MVPA in women with infants 2 - 12months old . METHODS From 2008 to 2011 , women ( n=311 ) with infants ( average age=5.7months ) from Honolulu , Hawaii were r and omly assigned to receive tailored telephone calls and access to a mom-centric website ( n=154 ) or access to a st and ard PA website ( n=157 ) . MVPA was measured at baseline , 6 , and 12months using self-report and acclerometers . RESULTS Controlling for covariates , the tailored condition significantly increased self-reported MVPA from an average of 44 to 246min/week compared with 46 to 156min/week for the st and ard condition ( p=0.027 ) . Mothers with≥2 children had significantly greater increases in MVPA in response to the tailored intervention than those with one child  ( p=0.016 ) . Accelerometer-measured MVPA significantly increased over time ( p=0.0001 ) , with no condition differences . There was evidence of reactivity to initially wearing accelerometers ; the tailored intervention significantly increased MVPA among women with low baseline accelerometer MVPA minutes , but not among those with high minutes ( pinteraction=0.053 ) . CONCLUSION A tailored intervention effectively increased MVPA over 12months in multiethnic women with infants , particularly those with more than one child Background Studies relating physical activity ( PA ) to  weight gain in children have produced mixed results , although there is some evidence for stronger associations with more intense physical activities . The present study tested the hypothesis that weight gain over one year in 8–10 year olds would be more strongly predicted by moderate and vigorous physical activity ( MVPA ) than total physical activity ( total PA ) or sedentary behaviour . Methodology Participants were 280 children taking part in the Physical Exercise and Appetite in Children Study ( PEACHES ) .  Weight status was assessed using body mass index ( BMI ) , fat mass index ( FMI ) , and waist circumference ( WC ) in school Year 4 ( baseline ; age 8.7 yrs ) and Year 5 ( follow-up ; age 9.7 yrs ) .  Physical activity  was measured at baseline using the Actigraph GT1 M accelerometer to assess total PA ( mean accelerometers counts per minute ) , MVPA ; ≥4000 counts per minute ) and sedentary time  ( < 100 counts per minute ) . Principal Findings After adjustment for baseline BMI , SES , sex and ethnicity , MVPA  was significantly associated with follow – up BMI ( adjusted β = −0.07 ; p = 0.002 ) . This association was independent of total PA or sedentary time  . Similar results were observed for FMI ; again MVPA was significantly associated with follow up FMI ( β = −0.16 ; p = 0.001 ) independent  of total PA or sedentary time . The pattern was similar for WC ( β = −0.07 ) , but the association between MVPA and WC did not reach significance at p = 0.06 . Conclusion The results of this study strongly support promotion of MVPA in children The aim of this study was to examine modifiable biological , psychological , behavioral and social-environmental correlates of physical activity among 1129 Norwegian 11-year-old children within a cross-sectional sample from the HEalth In Adolescents study .  Physical activity was assessed by accelerometer , and weight and height were measured objective ly . Age- and gender-specific cut-off points proposed by the International Obesity Task Force were used to define body mass index . Social-environmental variables were self-reported by question naire . Hierarchical regression ( linear mixed models ) revealed that normal weight children scored higher on percentage daily moderate-to-vigorous physical activity [ % daily moderate to vigorous physical activity ( MVPA ) ] than overweight/obese children ( P<0.001 ) . Self-efficacy ( P<0.01 ) and perceived social support from friends ( P<0.01 ) were positively associated with children 's % daily MVPA , and a negative association was found for computer/game-use on weekends ( P<0.01 ) . A moderator effect of weight category ( normal vs overweight/obese ) in the relationship between computer/game-use on weekends and % daily MVPA was detected ( P<0.05 ) , reflecting that higher computer/game-use on weekends was associated with lower % MVPA among the overweight/obese , but not among the normal weight . Modifiable correlates from multiple domains accounted for 14 % of the variance in % daily MVPA . Prospect i ve and intervention studies are needed to examine whether these factors act as mediators for physical activity change in pre-adolescent children Objective : To compare the effects of behavioral interventions targeting decreased sedentary behavior versus increased moderate-to-vigorous intensity physical activity ( MVPA ) in older adults . Method : Inactive older adults ( N = 38 , 68 ± 7 years old , 71 % female ) were r and omized to 12-week interventions targeting decreased sedentary behavior ( Sit Less ) or increased MVPA ( Get Active ) . The SenseWear armb and was used to objective ly assess activity in real time . Assessment s included a blinded armb and , the Community Health Activites Model Program for Senior ( CHAMPS ) question naire , 400-meter walk , and the Short Physical Performance Battery ( SPPB ) . Results : Objective ly measured MVPA increased in Get Active ( 75 ± 22 min/week , p < .001 ) ; self-reported MVPA increased in both groups ( p < .05 ) . Sedentary behavior did not change in either group ( all p > .05 ) . Only the Sit Less group improved the SPPB score ( 0.5 ± 0.3 , p = .046 ) . Discussion : Targeting reduced sedentary behavior had a greater effect on physical function among inactive but high functioning older adults over 12 weeks . Future studies of longer duration and combining increased MVPA with reduced sedentary behavior are needed BACKGROUND The importance of variation in total volume of physical activity or moderate- to vigorous-intensity physical activity ( MVPA ) to development of body fatness in childhood is unclear , and it is unclear if physical activity has a greater influence on adiposity in boys than girls . PURPOSE To assess relationships between 2-year changes in objective ly measured physical activity , sedentary behavior , and adiposity in English children . METHODS Prospect i ve cohort study , set in Northeast Engl and , of a socioeconomically representative sample of 403 children . Measures were change in accelerometer-determined physical activity and sedentary behavior  from age 7 to 9 years ( data collected 2006/2007 and 2008/2009 ; analyzed in 2010 ) and concurrent change in adiposity ( fat mass index derived from bioelectric impedance ) and change in BMI Z-score . RESULTS Decline in MVPA was associated with a greater increase in fat mass index in boys but not girls . Declining MVPA was associated with increased BMI Z-score in boys but not girls . Increased sedentary behavior was not associated with increased BMI Z-score in either gender . CONCLUSIONS Avoiding mid-late childhood reductions in MVPA may reduce excessive fat gain , although such strategies may have greater impact on boys than girls OBJECTIVE Low levels of physical activity appear to be associated with insulin resistance . However , the detailed associations of these complex relationships remain elusive . We examined the prospect i ve associations between self-reported TV viewing time , objective ly measured time spent sedentary , at light-intensity activity , and at moderate- and vigorous-intensity physical activity ( MVPA ) with insulin resistance . RESEARCH DESIGN AND METHODS In 192 individuals ( 81 men and 111 women ) with a family history of type 2 diabetes , we measured  physical activity and anthropometric and metabolic variables at baseline and after 1 year of follow-up in the ProActive UK trial . Physical activity  was measured objective ly by accelerometry . Insulin resistance was expressed as fasting insulin and the homeostasis model assessment score ( HOMA-IR ) . RESULTS Baseline MVPA was a significant predictor of fasting insulin at follow-up ( β = −0.004 [ 95 % CI −0.007 to −0.0001 ] , P = 0.022 ) , and the association approached significance for HOMA-IR ( β = −0.003 [ −0.007 to 0.000002 ] , P = 0.052 ) , independent of time spent sedentary , at light-intensity activity , sex , age , smoking status , waist circumference , and self-reported TV viewing . Time spent sedentary and at light-intensity activity were not significantly associated with insulin resistance . The change in MVPA between baseline and follow-up was inversely related to fasting insulin ( β = −0.003 [ −0.007 to −0.0003 ] , P = 0.032 ) and the HOMA-IR score ( β = −0.004 [ −0.008 to −0.001 ] , P = 0.015 ) at follow-up , after adjustment for baseline phenotype in addition to the same confounders as above . CONCLUSIONS These results highlight the importance of promoting moderate-intensity activity such as brisk walking for improving insulin sensitivity and possibly other metabolic risk factors to prevent type 2 diabetes A Play Street is a street that is reserved for children ’s safe play for a specific period during school vacations . It was hypothesized that a Play Street near children ’s home can increase their moderate- to vigorous-intensity physical activity ( MVPA ) and decrease their sedentary time . Therefore , the aim of this study was to investigate the effect of Play Streets on children ’s MVPA and sedentary time .  A nonequivalent control group pretest-posttest design was used to determine the effects of Play Streets on children ’s MVPA and sedentary time . Data were collected in Ghent during July and August 2013 . The study sample consisted of 126 children ( 54 from Play streets , 72 from control streets ) . Children wore an accelerometer for 8 consecutive days and their parents fill out a question naire before and after the measurement period . During the intervention , streets were enclosed and reserved for children ’s play . Four-level ( neighborhood – household – child – time of measurement ( no intervention or during intervention ) ) linear regression models were conducted in MLwiN to determine intervention effects . Positive intervention effects were found for sedentary time ( β = -0.76 ± 0.39 ; χ2 = 3.9 ; p = 0.05 ) and MVPA ( β = 0.82 ± 0.43 ; χ2 = 3.6 ; p = 0.06 ) . Between 14h00 and 19h00 , MVPA from children living in Play Streets increased from 27 minutes during normal conditions to 36 minutes during the Play Street intervention , whereas control children ’s MVPA decreased from 27 to 24 minutes . Sedentary time from children living in the Play Street decreased from 146 minutes during normal conditions to 138 minutes during the Play Street intervention , whereas control children ’s sedentary time increased from 156 minutes to 165 minutes . The intervention effects on MVPA ( β = -0.62 ± 0.25 ; χ2 = 6.3 ; p = 0.01 ) and sedentary time ( β = 0.85 ± 0.0.33 ; χ2 = 6.6 ; p = 0.01 ) remained significant when the effects were investigated during the entire day , indicating that children did not compensate for their increased MVPA and decreased sedentary time , during the rest of the day . Creating a safe play space near urban children ’s home by the Play Street intervention is effective in increasing children ’s MVPA and decreasing their sedentary time The aims of this study were to investigate whether  physical activity ( PA ) and sedentary time ( ST )  in 9- and 15-year-olds differed between 2005 - 2006 and 2011 - 2012 ( secular change ) , and to investigate changes in PA and ST from age 9 to 15 ( longitudinal change ) . In 2005 - 2006 , we invited nationally representative sample s of Norwegian 9- ( n=1470 ) and 15-year-olds ( n=1348 ) to participate . In 2011 - 2012 , we invited a new nationally representative sample of 9-year-olds ( n=1945 ) , whereas 15-year-olds ( n=1759 ) were invited to participate either based on previous participation in 2005 - 2006 or from a r and om sample of schools . We assessed PA and ST objective ly using accelerometers . In 2011 - 2012 , both 9- and 15-year-olds spent more time sedentary ( ≥35.7 min/d , P<.001 ) and less time in light PA ( ≥35.2 min/d , P<.001 ) compared to their peers in 2005 - 2006 . Nine-year-old girls also spent less time in moderate-to-vigorous PA ( MVPA ) ( 4.2 min/d , P=.041 ) . In both age groups , the proportion accumulating an average of 60 min/d of MVPA did not differ between the two cohorts . From age 9 to 15 , girls and boys decreased their time spent in LPA ( ≥106.7 min/d , P<.001 ) and in MVPA ( ≥20.8 min/d , P<.001 ) . During the same period , ST increased by a mean of > 2 h/d ( P<.011 ) . We observed an adverse secular change in PA from 2005 - 2006 to 2011 - 2012 among 9- and 15-year-olds , and a large decline in PA in the participants followed longitudinally from age 9 to 15 years Background : Physical activity ( PA ) and sedentary time ( SED ) have both been suggested as potential risk factors for adiposity in children . However , there is paucity of data examining the temporal associations between these variables . Objective : This study aim ed to analyze the cross-sectional and prospect i ve associations between PA , SED and body composition in children . Methods : A total of 510 children ( age at baseline 10.1±0.8 , age at follow-up 11.8±0.9 ) from six Portuguese schools from the Oeiras Municipality participated in this study .  PA and SED were measured by accelerometry and trunk fat mass ( TFM ) and body fat mass ( BFM )  were measured by dual energy X-ray absorptiometry .  Fat mass index ( FMI ) was calculated as BFM divided by height squared . Several regression models adjusted for age , sex , maturity status , follow-up duration , baseline levels of the outcome variable and SED or moderate to vigorous PA ( MVPA ) were performed . Results : MVPA ( min per day ) was cross-sectionally inversely associated with adiposity indexes ( FMI , TFM and BFM ) . Adiposity indexes were inversely associated with time in MVPA . In prospect i ve analyses , MVPA was associated with a lower levels of FMI ( β=−0.37 , 95 % confidence interval ( CI ) : −0.49 to −0.26 , P<0.001 ) , TFM ( β=−0.20 , 95 % CI : −0.29 to −0.10 , P<0.001 ) and BFM ( β=−0.37 , 95 % CI : −0.49 to −0.26 , P<0.001 ) . When the model was adjusted for age , sex , maturity status and for baseline levels of the outcome variables MVPA remained a significant predictor of lower adiposity indexes ( FMI : β=−0.09 , 95 % CI : −0.16 to −0.01 , P<0.05 ; TFM : β=−0.08 , 95 % CI : −0.15 to −0.01 , P<0.05 ; BFM : β=−0.07 , 95 % CI : −0.15 to 0.00 , P<0.05 ) . Adiposity was not associated  with MVPA when modeled as the exposure in prospect i ve analyses . SED was not related with adiposity indexes , except for the relationship with FMI . Conclusions : In cross-sectional and prospect i ve analyses , MVPA is associated with lower adiposity independent of covariates and SED . Results suggest that promoting MVPA is important for preventing gain in adiposity in healthy children 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 Abstract Recent attention has highlighted the importance of reducing sedentary time for maintaining health and quality of life . However , it is unclear how changing sedentary behavior may influence executive functions and self-regulatory strategy use , which are vital for the long-term maintenance of a health behavior regimen . The purpose of this cross-sectional study is to examine the estimated self-regulatory and executive functioning effects of substituting 30 min of sedentary behavior with 30 min of light activity , moderate-to-vigorous physical activity ( MVPA ) , or sleep in a sample of older adults . This study reports baseline data collected from low-active healthy older adults ( N = 247 , mean age 65.4 ± 4.6 years ) recruited to participate in a 6 month r and omized controlled exercise trial examining the effects of various modes of exercise on brain health and function . Each participant completed assessment s of  physical activity self-regulatory strategy use ( i.e. ,  self-monitoring , goal - setting , social support , reinforcement , time management , and relapse prevention )  and executive functioning . Physical activity and sedentary behaviors  were measured using accelerometers during waking hours for seven consecutive days at each time point . Isotemporal substitution analyses were conducted to examine the effect on self-regulation and executive functioning should an individual substitute sedentary time with light activity , MVPA , or sleep . The substitution of sedentary time with both sleep and MVPA influenced both self-regulatory strategy use and executive functioning . Sleep was associated with greater self-monitoring ( B = .23 , p = .02 ) , goal - setting ( B = .32 , p < .01 ) , and social support ( B = .18 , p = .01 ) behaviors . Substitution of sedentary time with MVPA was associated with higher accuracy on 2-item ( B = .03 , p = .01 ) and 3-item ( B = .02 , p = .04 ) spatial working memory tasks , and with faster reaction times on single ( B = −23.12 , p = .03 ) and mixed-repeated task-switching blocks ( B = −27.06 , p = .04 ) . Substitution of  sedentary  time with sleep was associated with marginally faster reaction time on mixed-repeated task-switching blocks ( B = −12.20 , p = .07 ) and faster reaction time on mixed-switch blocks ( B = 17.21 , p = .05 ) , as well as reduced global reaction time switch cost ( B = −16.86 , p = .01 ) . Substitution for light intensity physical activity did not produce significant effects . By replacing sedentary time with sleep and MVPA , individuals may bolster several important domains of self-regulatory behavior and executive functioning . This has important implication s for the design of long-lasting health behavior interventions . Trial Registration clinical trials.gov identifier NCT00438347
MVPA in children/adolescents with chronic disease appear to be well below guideline recommendations , although comparable with activity levels of their healthy peers except for children with malignancies .
CONTEXT Moderate-to-vigorous physical activity ( MVPA ) and sedentary time ( ST )  are important for child and adolescent health .
OBJECTIVE To examine habitual levels of accelerometer measured MVPA and ST  in children and adolescents with chronic disease , and how these levels compare with healthy peers .