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 .
A prospective examination of children's time spent outdoors, objectively measured physical activity and overweight
Objective : This study aim ed to determine whether time spent outdoors was associated with objective ly measured physical activity , body mass index ( BMI ) z-score and overweight in elementary-school aged children , cross-sectionally and prospect ively over 3 years . Methods : Three-year cohort study with data collected during 2001 and 2004 . Nineteen r and omly selected state elementary schools across Melbourne , Australia . One hundred and eighty eight 5–6-year-old and 360 10–12-year-old children . Baseline parent reports of children 's time spent outdoors  during warmer and cooler months , on weekdays and weekends . At baseline and follow-up , children 's moderate and vigorous physical activity ( MVPA ) was objective ly assessed by accelerometry , and BMI z-score and overweight was calculated from measured height and weight . Results : Cross-sectionally , each additional hour outdoors on weekdays and weekend days during the cooler months was associated with an extra 27 min week−1 MVPA among older girls , and with an extra 20 min week−1 MVPA among older boys . Longitudinally , more time outdoors on weekends predicted higher MVPA on weekends among older girls and boys ( 5 min week−1 ) . The prevalence of overweight among older children at follow-up was 27–41 % lower among those spending more time outdoors at baseline . Conclusion : Encouraging 10–12-year-old children to spend more time outdoors may be an effective strategy for increasing physical activity and preventing increases in overweight and obesity . Intervention research investigating the effect of increasing time outdoors on children 's physical activity and overweight is warranted
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 .