Conclusions Multicomponent interventions which also include the use of st and ing desks may be an effective method for reducing  children 's sedentary time  in a school-based intervention .
Introduction Prolonged , uninterrupted periods of sedentary time may be associated with increased risk of Type II diabetes , cardiovascular disease and all-cause mortality even if the minimum recommended levels of daily physical activity are achieved .
It is reported that children spend approximately 80 % of their day engaged in sedentary behaviours .
Since children spend a large portion of their waking time at school , school-based interventions targeting excessive or interrupted periods of sedentary time have been investigated in a number of studies .
However , results of the effectiveness of studies to- date have been inconsistent .
Aim To conduct a systematic review to evaluate the effectiveness of school-based interventions design ed to reduce sedentary behaviour on objective ly measured sedentary time in children .
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
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
Conclusions Multicomponent interventions which also include the use of st and ing desks may be an effective method for reducing  children 's sedentary time  in a school-based intervention .
Introduction Prolonged , uninterrupted periods of sedentary time may be associated with increased risk of Type II diabetes , cardiovascular disease and all-cause mortality even if the minimum recommended levels of daily physical activity are achieved .
It is reported that children spend approximately 80 % of their day engaged in sedentary behaviours .
Since children spend a large portion of their waking time at school , school-based interventions targeting excessive or interrupted periods of sedentary time have been investigated in a number of studies .
However , results of the effectiveness of studies to- date have been inconsistent .
Aim To conduct a systematic review to evaluate the effectiveness of school-based interventions design ed to reduce sedentary behaviour on objective ly measured sedentary time in children .