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 .
Examining the validity of the ActivPAL monitor in measuring posture and ambulatory movement in children
Background Decreasing sedentary activities that involve prolonged sitting may be an important strategy to reduce obesity and other physical and psychosocial health problems in children . The first step to underst and ing the effect of sedentary activities on children ’s health is to objective ly assess these activities with a valid measurement tool . Purpose To examine the validity of the ActivPAL monitor in measuring sitting/lying , st and ing , and walking time , transition counts and step counts in children in a laboratory setting . Methods Twenty five healthy elementary school children ( age 9.9 ± 0.3 years ; BMI 18.2 ± 1.9 ; mean ± SD ) were r and omly recruited across the Auckl and region , New Zeal and . Children were fitted with ActivPAL monitors and observed during simulated free-living activities involving sitting/lying , st and ing and walking , followed by treadmill and over-ground activities at various speeds ( slow , normal , fast ) against video observation ( criterion measure ) . The ActivPAL sit-to-st and and st and -to-sit transition counts and steps were also compared with video data . The accuracy of step counts measured by the ActivPAL was also compared against the New Lifestyles NL-2000 and the Yamax Digi-Walker SW-200 pedometers . Results We observed a perfect correlation between the ActivPAL monitor in time spent sitting/lying , st and ing , and walking in simulated free-living activities with direct observation . Correlations between the ActivPAL and video observation in total numbers of sit-to-st and and st and -to-sit transitions were high ( r = 0.99 ± 0.01 ) . Unlike pedometers , the ActivPAL did not misclassify fidgeting as steps taken . Strong correlations ( r = 0.88 - 1.00 ) between ActivPAL step counts and video observation in both treadmill and over-ground slow and normal walking were also observed . During treadmill and over-ground fast walking and running , the correlations were low ( r = 0.21 - 0.46 ) . Conclusion The ActivPAL monitor is a valid measurement tool for assessing time spent sitting/lying , st and ing , and walking , sit-to-st and and st and -to-sit transition counts and step counts in slow and normal walking . The device did not measure accurately steps taken during treadmill and over-ground fast walking and running in children
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 .