METHODS The results of recent systematic review s are discussed and supplemented with relevant literature not included in these review s. PubMed was search ed for the years 2006 - 2011 for additional topics not sufficiently covered by the review s. RESULTS PA was associated with lower blood pressure and a healthier lipid blood profile in children .
The association was stronger when a composite risk factor score was analysed , and the associations between physical fitness and cardiovascular disease ( CVD ) risk factors were even stronger .
Muscle strength and endurance exercise each had an effect on blood lipids and insulin sensitivity even if the effect was smaller for muscle strength than for aerobic exercise .
New evidence suggests possible effects of PA  on C-reactive protein .
CONCLUSION There is accumulating evidence that PA can have beneficial effects on the risk factors of CVD in children .
BACKGROUND A number of recent systematic review s have result ed in changes in international recommendations for children 's participation in physical activity ( PA ) for health .
The World Health Authority ( WHO ) has recently released new recommendations .
The WHO still recommends 60 min of moderate to vigorous physical activity ( MVPA ) , but also emphasises that these minutes should be on top of everyday physical activities .
Everyday physical activities total around 30 min of MVPA in the quintile of the least active children , which means that the new recommendations constitute more activity in total compared with earlier recommendations .
OBJECTIVE To summarise evidence justifying new PA recommendation for cardiovascular health in children .
Training, muscle volume, and energy expenditure in nonobese American girls.
Little is known about the relationship among  training  , energy expenditure , muscle volume , and fitness in prepubertal girls . Because physical activity is high in prepubertal children , we hypothesized that there would be no effect of training . Forty pre- and early pubertal ( mean age 9.1 + /- 0.1 yr ) nonobese girls enrolled in a 5 day/wk summer school program for 5 wk and were r and omized to control ( n = 20 ) or training groups ( n = 20 ; 1.5 h/day , endurance-type exercise )  .  Total energy expenditure ( TEE ) was measured using doubly labeled water , thigh muscle volume using magnetic resonance imaging , and peak O(2 ) uptake ( VO(2 peak ) ) using cycle ergometry .  TEE was significantly greater ( 17 % , P < 0.02 ) in the training girls . Training increased thigh muscle volume ( + 4.3 + /- 0.9 % , P < 0.005 ) and VO(2 peak ) ( + 9.5 + /- 6 % , P < 0.05 ) , effects surprisingly similar to those observed in adolescent girls using the same protocol ( Eliakim A , Barstow TJ , Brasel JA , Ajie H , Lee W-NP , Renslo R , Berman N , and Cooper DM , J Pediatr 129 : 537 - 543 , 1996 ) . We further compared these two sample population s : thigh muscle volume per weight was much lower in adolescent compared with prepubertal girls ( 17.0 + /- 0.3 vs. 27.8 + /- 0.6 ml/kg body mass ; P < 0.001 ) , and allometric analysis revealed remarkably low scaling factors relating muscle volume ( 0.34 + /- 0.05 , P < 0.0001 ) , TEE ( 0.24 + /- 0 . 06 , P < 0.0004 ) , and VO(2 peak ) ( 0.28 + /- 0.07 , P < 0.0001 ) to body mass in all subjects . Muscle and cardiorespiratory functions were quite responsive to brief training in prepubertal girls . Moreover , a retrospective , cross-sectional analysis suggests that increases in muscle mass and VO(2 peak ) may be depressed in nonobese American girls as they mature
METHODS The results of recent systematic review s are discussed and supplemented with relevant literature not included in these review s. PubMed was search ed for the years 2006 - 2011 for additional topics not sufficiently covered by the review s. RESULTS PA was associated with lower blood pressure and a healthier lipid blood profile in children .
The association was stronger when a composite risk factor score was analysed , and the associations between physical fitness and cardiovascular disease ( CVD ) risk factors were even stronger .
Muscle strength and endurance exercise each had an effect on blood lipids and insulin sensitivity even if the effect was smaller for muscle strength than for aerobic exercise .
New evidence suggests possible effects of PA  on C-reactive protein .
CONCLUSION There is accumulating evidence that PA can have beneficial effects on the risk factors of CVD in children .
BACKGROUND A number of recent systematic review s have result ed in changes in international recommendations for children 's participation in physical activity ( PA ) for health .
The World Health Authority ( WHO ) has recently released new recommendations .
The WHO still recommends 60 min of moderate to vigorous physical activity ( MVPA ) , but also emphasises that these minutes should be on top of everyday physical activities .
Everyday physical activities total around 30 min of MVPA in the quintile of the least active children , which means that the new recommendations constitute more activity in total compared with earlier recommendations .
OBJECTIVE To summarise evidence justifying new PA recommendation for cardiovascular health in children .