The systematic review revealed overall positive effects of outdoor time  on physical activity , sedentary behaviour , and cardiorespiratory fitness , although causality could not be assumed due to a lack of RCTs .
Motor skill development was unrelated to outdoor time ; however , this relationship was only examined in a single study of preschool children .
No studies were found that examined associations between outdoor time and musculoskeletal fitness
The objective of this systematic review was to examine the relationship between outdoor time and : ( 1 ) physical activity , ( 2 ) cardiorespiratory fitness , ( 3 ) musculoskeletal fitness , ( 4 ) sedentary behaviour ; or ( 5 ) motor skill development in children aged 3 - 12 years .
Physical activity and its correlates in children: a cross-sectional study (the GINIplus & LISAplus studies)
Background Physical inactivity  among children is an increasing problem that adversely affects children ’s health . A better underst and ing of factors which affect  physical activity ( PA ) will help create effective interventions aim ed at raising the activity levels of children . This cross-sectional study examined the associations of PA with individual ( biological , social , behavioral , psychological ) and environmental ( East vs. West Germany , rural vs. urban regions ) characteristics in children . Methods Information on PA and potential correlates was collected from 1843 girls and 1997 boys using question naires during the 10-year follow-up of two prospect i ve birth cohort studies ( GINIplus and LISAplus ) . Study regions represent urban and rural sites as well as East and West of Germany . Logistic regression modeling was applied to examine cross-sectional associations between individual as well as environmental factors and  PA levels . Results Five of fourteen variables were significantly associated with  PA .  Among children aged 10 , girls tended to be less active than boys , especially with respect to vigorous PA ( OR = 0.72 for summer ) . Children who were not a member of a sports club showed a substantially reduced amount of PA in winter ( OR = 0.15 ) . Rural environments promote moderate PA  , particularly in winter ( OR = 1.88 ) , whereas an increased time outdoors primarily promotes moderate PA in summer ( OR = 12.41 ) . Children with abnormal emotional symptoms  exhibited reduced physical activity , particularly in winter ( OR = 0.60 ) . BMI , puberty , parental BMI , parental education , household income , siblings , TV/PC consumption , and method of arriving school , were not associated with PA . Conclusions When considering correlates of PA from several domains simultaneously , only few factors ( sex , sports club membership , physical environment , time outdoors , and emotional symptoms ) appear to be relevant . Although the causality needs to be ascertained in longitudinal studies , variables which can not be modified should be used to identify risk groups while modifiable variables , such as sports club activities , may be addressed in intervention programs
The systematic review revealed overall positive effects of outdoor time  on physical activity , sedentary behaviour , and cardiorespiratory fitness , although causality could not be assumed due to a lack of RCTs .
Motor skill development was unrelated to outdoor time ; however , this relationship was only examined in a single study of preschool children .
No studies were found that examined associations between outdoor time and musculoskeletal fitness
The objective of this systematic review was to examine the relationship between outdoor time and : ( 1 ) physical activity , ( 2 ) cardiorespiratory fitness , ( 3 ) musculoskeletal fitness , ( 4 ) sedentary behaviour ; or ( 5 ) motor skill development in children aged 3 - 12 years .