human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Sedentary behavior is a risk factor for cardiometabolic disease . Regularly interrupting sedentary behavior with activity breaks may lower this risk . OBJECTIVE We compared the effects of prolonged sitting , continuous physical activity combined with prolonged sitting , and regular activity breaks on  postpr and ial metabolism . DESIGN Seventy adults participated in a r and omized crossover study . The prolonged sitting intervention involved sitting for 9 h , the physical activity intervention involved walking for 30 min and then sitting , and the regular-activity-break intervention involved walking for 1 min 40 s every 30 min . Participants consumed a meal-replacement beverage at 60 , 240 , and 420 min . RESULTS The plasma incremental area under the curve ( iAUC ) for insulin differed between interventions ( overall P < 0.001 ) . Regular activity breaks lowered values by 866.7 IU · L(-1 ) · 9 h(-1 ) ( 95 % CI : 506.0 , 1227.5 IU · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with prolonged sitting and by 542.0 IU · L(-1 ) · 9 h(-1 ) ( 95 % CI : 179.9 , 904.2 IU · L(-1 ) · 9 h(-1 ) ; P = 0.003 ) when compared with physical activity . Plasma glucose iAUC also differed between interventions ( overall P < 0.001 ) . Regular activity breaks  lowered values by 18.9 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 10.0 , 28.0 mmol · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with prolonged sitting and by 17.4 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 8.4 , 26.3 mmol · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with physical activity . Plasma triglyceride iAUC differed between interventions ( overall P = 0.023 ) . Physical activity  lowered values by 6.3 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 1.8 , 10.7 mmol · L(-1 ) · 9 h(-1 ) ; P = 0.006 ) when compared with regular activity breaks . CONCLUSION Regular activity breaks were more effective than continuous physical activity at decreasing postpr and ial glycemia and insulinemia in healthy , normal-weight adults . This trial was registered with the Australian New Zeal and Clinical Trials registry as ACTRN12610000953033 Background The activPAL has been identified as an accurate and reliable measure of sedentary behaviour . However , only limited information is available on the accuracy of the activPAL activity count function as a measure of physical activity , while no unit calibration of the activPAL has been completed to date . This study aim ed to investigate the criterion validity of the activPAL , examine the concurrent validity of the activPAL , and perform and vali date a value calibration of the activPAL in an adolescent female population . The performance of the activPAL in estimating posture was also compared with sedentary thresholds used with the ActiGraph accelerometer . Method ologies Thirty adolescent females ( 15 developmental ; 15 cross-validation ) aged 15–18 years performed 5 activities while wearing the activPAL , ActiGraph GT3X , and the Cosmed K4B2 . A r and om coefficient statistics model examined the relationship between metabolic equivalent ( MET ) values and activPAL counts . Receiver operating characteristic analysis was used to determine activity thresholds and for cross-validation . The r and om coefficient statistics model showed a concordance correlation coefficient of 0.93 ( st and ard error of the estimate = 1.13 ) . An optimal moderate threshold of 2997 was determined using mixed regression , while an optimal vigorous threshold of 8229 was determined using receiver operating statistics . The activPAL count function demonstrated very high concurrent validity ( r = 0.96 , p<0.01 ) with the ActiGraph count function . Levels of agreement for sitting , st and ing , and stepping between direct observation and the activPAL and ActiGraph were 100 % , 98.1 % , 99.2 % and 100 % , 0 % , 100 % , respectively . Conclusions These findings suggest that the activPAL is a valid , objective measurement tool that can be used for both the measurement of physical activity and sedentary behaviours in an adolescent female population OBJECTIVE Observational studies show breaking up prolonged sitting has beneficial associations with cardiometabolic risk markers , but intervention studies are required to investigate causality . We examined the acute effects on postpr and ial glucose and insulin levels of uninterrupted sitting compared with sitting interrupted by brief bouts of light- or moderate-intensity walking . RESEARCH DESIGN AND METHODS Overweight/obese adults ( n = 19 ) , aged 45–65 years , were recruited for a r and omized three-period , three-treatment acute crossover trial : 1 ) uninterrupted sitting ; 2 ) seated with 2-min bouts of light-intensity walking every 20 min ; and 3 ) seated with 2-min bouts of moderate-intensity walking every 20 min . A st and ardized test drink was provided after an initial 2-h period of uninterrupted sitting . The positive incremental area under curves ( iAUC ) for glucose and insulin ( mean [ 95 % CI ] ) for the 5 h after the test drink ( 75 g glucose , 50 g fat ) were calculated for the respective treatments . RESULTS The glucose iAUC ( mmol/L ) ⋅ h after both activity-break conditions was reduced ( light : 5.2 [ 4.1–6.6 ] ; moderate : 4.9 [ 3.8–6.1 ] ; both P < 0.01 ) compared with uninterrupted sitting ( 6.9 [ 5.5–8.7 ] ) . Insulin iAUC ( pmol/L ) ⋅ h was also reduced with both activity-break conditions ( light : 633.6 [ 552.4–727.1 ] ; moderate : 637.6 [ 555.5–731.9 ] , P < 0.0001 ) compared with uninterrupted sitting ( 828.6 [ 722.0–950.9 ] ) . CONCLUSIONS Interrupting sitting time with short bouts of light- or moderate-intensity walking  lowers postpr and ial glucose and insulin levels  in overweight/obese adults . This may improve glucose metabolism and potentially be an important public health and clinical intervention strategy for reducing cardiovascular risk Objectives Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers . Methods Forty children aged 4–6 years ( 5.3±1.0 years ) completed a ∼150-min room calorimeter protocol involving age-appropriate sedentary , light and moderate-to vigorous-intensity physical activities . Children wore an ActiGraph GT3X on the right mid-axillary line of the hip . Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods . Energy expenditure was predicted using Pate and Puyau equations . Physical activity intensity was classified using Evenson , Sirard , Van Cauwenberghe , Pate , Puyau , and Reilly , ActiGraph cut-points . Results The Pate equation significantly overestimated VO2 during sedentary behaviors , light physical activities and total VO2 ( P<0.001 ) . No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities ( P = 0.072 ) . The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities , light-intensity physical activities and total activity energy expenditure ( P<0.0125 ) . However , no overestimation of activity energy expenditure during sedentary behavior was found . The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others . Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others . Conclusion Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers . Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities , respectively , are recommended 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 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 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 sed 
    Output:
    
agent
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
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Sedentary behavior is a risk factor for cardiometabolic disease . Regularly interrupting sedentary behavior with activity breaks may lower this risk . OBJECTIVE We compared the effects of prolonged sitting , continuous physical activity combined with prolonged sitting , and regular activity breaks on  postpr and ial metabolism . DESIGN Seventy adults participated in a r and omized crossover study . The prolonged sitting intervention involved sitting for 9 h , the physical activity intervention involved walking for 30 min and then sitting , and the regular-activity-break intervention involved walking for 1 min 40 s every 30 min . Participants consumed a meal-replacement beverage at 60 , 240 , and 420 min . RESULTS The plasma incremental area under the curve ( iAUC ) for insulin differed between interventions ( overall P < 0.001 ) . Regular activity breaks lowered values by 866.7 IU · L(-1 ) · 9 h(-1 ) ( 95 % CI : 506.0 , 1227.5 IU · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with prolonged sitting and by 542.0 IU · L(-1 ) · 9 h(-1 ) ( 95 % CI : 179.9 , 904.2 IU · L(-1 ) · 9 h(-1 ) ; P = 0.003 ) when compared with physical activity . Plasma glucose iAUC also differed between interventions ( overall P < 0.001 ) . Regular activity breaks  lowered values by 18.9 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 10.0 , 28.0 mmol · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with prolonged sitting and by 17.4 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 8.4 , 26.3 mmol · L(-1 ) · 9 h(-1 ) ; P < 0.001 ) when compared with physical activity . Plasma triglyceride iAUC differed between interventions ( overall P = 0.023 ) . Physical activity  lowered values by 6.3 mmol · L(-1 ) · 9 h(-1 ) ( 95 % CI : 1.8 , 10.7 mmol · L(-1 ) · 9 h(-1 ) ; P = 0.006 ) when compared with regular activity breaks . CONCLUSION Regular activity breaks were more effective than continuous physical activity at decreasing postpr and ial glycemia and insulinemia in healthy , normal-weight adults . This trial was registered with the Australian New Zeal and Clinical Trials registry as ACTRN12610000953033 Background The activPAL has been identified as an accurate and reliable measure of sedentary behaviour . However , only limited information is available on the accuracy of the activPAL activity count function as a measure of physical activity , while no unit calibration of the activPAL has been completed to date . This study aim ed to investigate the criterion validity of the activPAL , examine the concurrent validity of the activPAL , and perform and vali date a value calibration of the activPAL in an adolescent female population . The performance of the activPAL in estimating posture was also compared with sedentary thresholds used with the ActiGraph accelerometer . Method ologies Thirty adolescent females ( 15 developmental ; 15 cross-validation ) aged 15–18 years performed 5 activities while wearing the activPAL , ActiGraph GT3X , and the Cosmed K4B2 . A r and om coefficient statistics model examined the relationship between metabolic equivalent ( MET ) values and activPAL counts . Receiver operating characteristic analysis was used to determine activity thresholds and for cross-validation . The r and om coefficient statistics model showed a concordance correlation coefficient of 0.93 ( st and ard error of the estimate = 1.13 ) . An optimal moderate threshold of 2997 was determined using mixed regression , while an optimal vigorous threshold of 8229 was determined using receiver operating statistics . The activPAL count function demonstrated very high concurrent validity ( r = 0.96 , p<0.01 ) with the ActiGraph count function . Levels of agreement for sitting , st and ing , and stepping between direct observation and the activPAL and ActiGraph were 100 % , 98.1 % , 99.2 % and 100 % , 0 % , 100 % , respectively . Conclusions These findings suggest that the activPAL is a valid , objective measurement tool that can be used for both the measurement of physical activity and sedentary behaviours in an adolescent female population OBJECTIVE Observational studies show breaking up prolonged sitting has beneficial associations with cardiometabolic risk markers , but intervention studies are required to investigate causality . We examined the acute effects on postpr and ial glucose and insulin levels of uninterrupted sitting compared with sitting interrupted by brief bouts of light- or moderate-intensity walking . RESEARCH DESIGN AND METHODS Overweight/obese adults ( n = 19 ) , aged 45–65 years , were recruited for a r and omized three-period , three-treatment acute crossover trial : 1 ) uninterrupted sitting ; 2 ) seated with 2-min bouts of light-intensity walking every 20 min ; and 3 ) seated with 2-min bouts of moderate-intensity walking every 20 min . A st and ardized test drink was provided after an initial 2-h period of uninterrupted sitting . The positive incremental area under curves ( iAUC ) for glucose and insulin ( mean [ 95 % CI ] ) for the 5 h after the test drink ( 75 g glucose , 50 g fat ) were calculated for the respective treatments . RESULTS The glucose iAUC ( mmol/L ) ⋅ h after both activity-break conditions was reduced ( light : 5.2 [ 4.1–6.6 ] ; moderate : 4.9 [ 3.8–6.1 ] ; both P < 0.01 ) compared with uninterrupted sitting ( 6.9 [ 5.5–8.7 ] ) . Insulin iAUC ( pmol/L ) ⋅ h was also reduced with both activity-break conditions ( light : 633.6 [ 552.4–727.1 ] ; moderate : 637.6 [ 555.5–731.9 ] , P < 0.0001 ) compared with uninterrupted sitting ( 828.6 [ 722.0–950.9 ] ) . CONCLUSIONS Interrupting sitting time with short bouts of light- or moderate-intensity walking  lowers postpr and ial glucose and insulin levels  in overweight/obese adults . This may improve glucose metabolism and potentially be an important public health and clinical intervention strategy for reducing cardiovascular risk Objectives Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers . Methods Forty children aged 4–6 years ( 5.3±1.0 years ) completed a ∼150-min room calorimeter protocol involving age-appropriate sedentary , light and moderate-to vigorous-intensity physical activities . Children wore an ActiGraph GT3X on the right mid-axillary line of the hip . Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods . Energy expenditure was predicted using Pate and Puyau equations . Physical activity intensity was classified using Evenson , Sirard , Van Cauwenberghe , Pate , Puyau , and Reilly , ActiGraph cut-points . Results The Pate equation significantly overestimated VO2 during sedentary behaviors , light physical activities and total VO2 ( P<0.001 ) . No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities ( P = 0.072 ) . The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities , light-intensity physical activities and total activity energy expenditure ( P<0.0125 ) . However , no overestimation of activity energy expenditure during sedentary behavior was found . The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others . Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others . Conclusion Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers . Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities , respectively , are recommended 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 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 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 sed 
    Output:
    