Overall , total PA was favourably associated with physical , psychological/social , and cognitive health indicators .
Relationships were more consistent and robust for higher ( e.g. , MVPA ) versus lower ( e.g. , LPA ) intensity PA .
All patterns of activity ( sporadic , bouts , continuous ) provided benefit .
LPA was favourably associated with cardiometabolic biomarkers ; data were scarce for other outcomes .
These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth , but also highlight the potential benefits of LPA and total PA .
Moderate-to-vigorous physical activity ( MVPA ) is essential for disease prevention and health promotion .
Emerging evidence suggests other intensities of physical activity ( PA ) , including light-intensity activity ( LPA ) , may also be important , but there has been no rigorous evaluation of the evidence .
The purpose of this systematic review was to examine the relationships between objective ly measured PA ( total and all intensities ) and health indicators in school-aged children and youth .
Online data bases were search ed for peer- review ed studies that met the a priori inclusion criteria : population ( apparently healthy , aged 5 - 17 years ) , intervention/exposure/comparator ( volumes , duration s , frequencies , intensities , and patterns of objective ly measured PA ) , and outcome ( body composition , cardiometabolic biomarkers , physical fitness , behavioural conduct/pro-social behaviour , cognition/academic achievement , quality of life/well-being , harms , bone health , motor skill development , psychological distress , self-esteem ) .
Strength Training and Physical Activity in Boys: a Randomized Trial
BACKGROUND : In developed societies levels of daily physical activity ( PA ) among school-age children are decreasing . This implies risk factors for cardiovascular and metabolic diseases . Specific strategies to improve levels of PA are needed . In prepubertal boys there is evidence that strength training increases spontaneous PA outside of training . METHODS : A total of 102 schoolchildren ( age 10–14 years ) in Switzerl and were r and omly assigned to  physical education classes or to participate twice weekly at a guided strength training program for 19 weeks  . Spontaneous PA energy expenditure ( PAEE ; 3axial accelerometry for 7 days ) , leg and arm strength , and body composition ( dual energy radiograph absorptiometry ) were measured at baseline , after 19 weeks of training intervention , and after 3 months of washout . RESULTS : There were no significant differences between the groups at baseline . In the intervention group , PAEE increased by 10 % from baseline to end of training in boys ( P = .02 ) , but not in girls . Leg and arm strength were increased owing to training intervention in both boys and girls . All other variables were unchanged . Baseline PAEE was significantly negatively correlated with changes of PAEE . CONCLUSIONS : Targeted strength training significantly increases daily spontaneous PA behavior in boys . The less active children showed the greatest increase in spontaneous PAEE . Girls showed a similar increase in strength , but not in spontaneous PAEE . This may be explained by their earlier pubertal development . Strength training may be a promising strategy in schools to counteract decreasing levels of PA
Overall , total PA was favourably associated with physical , psychological/social , and cognitive health indicators .
Relationships were more consistent and robust for higher ( e.g. , MVPA ) versus lower ( e.g. , LPA ) intensity PA .
All patterns of activity ( sporadic , bouts , continuous ) provided benefit .
LPA was favourably associated with cardiometabolic biomarkers ; data were scarce for other outcomes .
These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth , but also highlight the potential benefits of LPA and total PA .
Moderate-to-vigorous physical activity ( MVPA ) is essential for disease prevention and health promotion .
Emerging evidence suggests other intensities of physical activity ( PA ) , including light-intensity activity ( LPA ) , may also be important , but there has been no rigorous evaluation of the evidence .
The purpose of this systematic review was to examine the relationships between objective ly measured PA ( total and all intensities ) and health indicators in school-aged children and youth .
Online data bases were search ed for peer- review ed studies that met the a priori inclusion criteria : population ( apparently healthy , aged 5 - 17 years ) , intervention/exposure/comparator ( volumes , duration s , frequencies , intensities , and patterns of objective ly measured PA ) , and outcome ( body composition , cardiometabolic biomarkers , physical fitness , behavioural conduct/pro-social behaviour , cognition/academic achievement , quality of life/well-being , harms , bone health , motor skill development , psychological distress , self-esteem ) .