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 .
Active Commuting Throughout Adolescence and Central Fatness before Adulthood: Prospective Birth Cohort Study
Background Active commuting is a good opportunity to accumulate physical activity ( PA ) across the lifespan that potentially might influence central body fat . We aim ed to examine the prospect i ve associations of active commuting at 11 , 15 and 18 years of age with central body fat at 18 years . Methods Participants were part of a large birth cohort study in Pelotas , Brazil ( n = 3,649 participants ) .  Active commuting , leisure-time PA and income  were self-reported at 11 , 15 and 18 years . Waist circumference and trunk fat mass were collected at 18 years with the use of a 3-dimensional photonic scanner and dual-energy X-ray absorptiometry , respectively . Results Active commuting at 11 years was not prospect ively associated with central body fat . However , we found that active commuting at 15 and 18 years were prospect ively and cross-sectionally associated with central body fat variables , respectively , in boys but not in girls . Also , boys in the highest tertile of accumulated active commuting ( i.e. , average of active commuting at 11 , 13 and 18 years ) were associated with −2.09 cm ( 95%CI : −3.24 ; −0.94 ) of waist circumference and −1.11 kg ( 95%CI : −1.74 ; −0.48 ) of trunk fat mass compared to boys in the lowest tertile . Analyses on changes in tertiles of active commuting from 11 and 15 years to 18 years with central body fat variables at 18 years showed that boys who remained consistently in the highest tertile or moved to a higher tertile had lower levels of central body fat compared to those consistently in the lowest tertile . Conclusions Active commuting throughout adolescence in boys , especially during middle and late adolescence , is associated with lower levels in central fatness before adulthood
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 .