Question naires were the more predominant way to evaluate PA .
Most studies showed that PA promotes a protective effect against a higher BF gain .
CONCLUSION It was concluded that PA has a protective effect against BF with differences between the genders and according to the BF marker or measurement assessed ; higher intensity PA leads to a greater effect against BF gain in both genders ; and the maintenance or increase of PA level on BF observed through analysis of change in PA level yielded more consistent findings in the relation between PA and BF
BACKGROUND Physical activity ( PA ) practice has been inversely associated to body  fat ( BF ) and recommended as a way to reduce and prevent obesity .
The objective of this study was to conduct a systematic review on the association of  PA and BF in adolescence .
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
Question naires were the more predominant way to evaluate PA .
Most studies showed that PA promotes a protective effect against a higher BF gain .
CONCLUSION It was concluded that PA has a protective effect against BF with differences between the genders and according to the BF marker or measurement assessed ; higher intensity PA leads to a greater effect against BF gain in both genders ; and the maintenance or increase of PA level on BF observed through analysis of change in PA level yielded more consistent findings in the relation between PA and BF
BACKGROUND Physical activity ( PA ) practice has been inversely associated to body  fat ( BF ) and recommended as a way to reduce and prevent obesity .
The objective of this study was to conduct a systematic review on the association of  PA and BF in adolescence .