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 .
Effect of long-term leisure time physical activity on lean mass and fat mass in girls during adolescence.
The purpose of this 7-yr prospect i ve longitudinal study was to examine if the level and consistency of leisure-time physical activity ( LTPA ) during adolescence affected the quantity and distribution of lean mass ( LM ) and fat mass ( FM ) at early adulthood . The study subjects were 202 Finnish girls who were 10 - 13 yr old at baseline .  LM and FM of the total body ( TB ) , arms , legs , and trunk were assessed by dual-energy X-ray absorptiometry . Muscle cross-sectional area ( mCSA ) of the left leg was assessed by peripheral quantitative computed tomography . Scores of LTPA were obtained by question naire . Girls were divided into four groups comprising those with consistently low ( G(LL ) ) or consistently high ( G(HH ) ) physical activity , or those whose physical activity changed from low to high ( G(LH ) ) , or from high to low ( G(HL ) ) , over the 7 yr of follow-up . At baseline , no differences were found in LM , FM , and FM% among the groups in any of the body segments . By the end of the study G(HH ) and G(LH ) had higher values of LM of the TB , arms , legs , and trunk than that of the G(HL ) and G(LL ) groups ( P < 0.05 , respectively ) . High FM% of the TB was associated with low level of LTPA , but no significant differences were found in the absolute amount of FM and mCSA among the LTPA groups . Our results suggest that a consistently high level of  LTPA  during the transition from prepuberty to early adulthood has a positive effect on lean mass gain in girls . Participating in 5 h of LTPA per week had a significant effect on FM% but not on the absolute amount of fat mass
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 .