In conclusion , very little is known about sedentary behaviors other than screen time in this age group .
Although highly variable , findings suggest that children are already engaging in high levels of screen time by age 2 and the majority exceed current recommendations
Sedentary behavior has negative health outcomes , evident even in young children .
Identifying the prevalence of sedentary behavior in children < 2years is important for determining the necessity for intervention strategies .
The aim of this systematic review was to determine the prevalence of sedentary behavior in children < 2years .
Psychosocial correlates of physical activity in healthy children.
BACKGROUND Underst and ing the determinants of physical activity in children is critical for the treatment and prevention of childhood obesity . Social-cognitive theory has been used to underst and behavioral patterns in children . OBJECTIVES To explore the relationship between health beliefs , self-efficacy , social support , and sedentary activities and physical  activity levels in children and to examine the relationship between physical activity and  children 's  self-esteem . METHODS Ninety-two children aged 10 to 16 years completed the study .  Physical activity was monitored for 1 week with a motion detector ( Actitrac ; IM Systems , Baltimore , Md ) . Moderate-level activity and high-level activity were defined based on the results of treadmill testing . Health beliefs , self-efficacy , social influences , and time spent in sedentary behaviors were determined through question naires . Self-esteem was measured using the Piers-Harris Children 's Self-Concept Scale . Chronic anxiety was measured with the Revised Children 's Manifest Anxiety Scale . RESULTS There was a significant decline in physical activity levels between ages 10 and 16 years , particularly in girls . Preteen girls spent approximately 35 % more time in low- and high-level activity than did teenage girls ( P<.001 ) . Overall , children spent 75.5 % of the day inactive , with a mean + /- SD of 5.2 + /- 1.8 hours watching television , sitting at the computer , and doing homework . In contrast , only 1.4 % of the day ( 12.6 + /- 12.2 minutes ) was spent in vigorous activity . Time spent in sedentary behaviors was inversely correlated with the amount of moderate-level activity ( P<.001 ) but not high-level activity . In contrast , time spent in high-level activity correlated with self-efficacy scores ( P<.001 ) and social influences scores ( P<.005 ) . High-level physical activity was also associated with improved self-esteem ( P<.05 ) . Higher health beliefs scores were not correlated with physical activity levels . CONCLUSIONS Children and adolescents are largely sedentary . Correlates of high- and low-level physical activity are different . Time spent on sedentary activities is inversely correlated with moderate-level activity , while self-efficacy and social influences are positively correlated with more intense physical activity . In addition , increased high-level physical activity is an important component in the development of self-esteem in children
In conclusion , very little is known about sedentary behaviors other than screen time in this age group .
Although highly variable , findings suggest that children are already engaging in high levels of screen time by age 2 and the majority exceed current recommendations
Sedentary behavior has negative health outcomes , evident even in young children .
Identifying the prevalence of sedentary behavior in children < 2years is important for determining the necessity for intervention strategies .
The aim of this systematic review was to determine the prevalence of sedentary behavior in children < 2years .