Physical activity interventions were consistently ( > 60 % of studies ) associated with improved motor and cognitive development , and psychosocial and cardiometabolic health .
Across observational studies , physical activity was consistently associated with favourable motor development , fitness , and bone and skeletal health .
For intensity , light- and moderate-intensity physical activity were not consistently associated with any health indicators , whereas moderate- to vigorous-intensity , vigorous-intensity , and total physical activity were consistently favourably associated with multiple health indicators .
Across study design s , consistent favourable associations with health indicators were observed for a variety of types of physical activity , including active play , aerobic , dance , prone position ( infants ; ≤1 year ) , and structured/organized .
Apart from ≥30 min/day of the prone position for infants , the most favourable frequency and duration of physical activity was unclear .
However , more physical activity appeared better for health .
Conclusions Specific types of physical activity , total physical activity , and physical activity of at least moderate- to vigorous-intensity were consistently favourably associated with multiple health indicators .
Background Given the rapid development during the early years ( 0 - 4 years ) , an underst and ing of the health implication s of physical activity is needed .
The purpose of this systematic review was to examine the relationships between objective ly and subjectively measured physical activity and health indicators in the early years .
Longitudinal study of calcium intake, physical activity, and bone mineral content in infants 6-18 months of age.
Although increased physical activity early in life is recommended for optimizing bone health , no controlled trials on the effect of activity on bone mass accretion during periods of rapid growth have been reported . The purpose of this study was to determine whether infants r and omized to a 1 year gross motor activity program  had a greater bone mass accretion than infants r and omized to a fine motor activity program .  The gross motor program included activities that focused on loading the skeleton and were performed for 15 - 20 minutes/day , 5 days/week by study personnel . Infants ( n = 72 ) were enrolled at 6 months of age , and total body bone mineral content ( BMC ) , 3-day diet records , and activity levels were obtained at 6 , 9 , 12 , 15 , and 18 months . BMC was associated with weight , length , and bone area at all ages and correlated with earlier calcium intakes . Calcium intake appeared to modify the effect of  gross motor activity  on bone mass accretion ; infants in both groups had similar bone accretion at moderately high calcium intakes , but at low calcium intakes infants in the gross motor program had less bone accretion than infants in the fine motor program . Compliant infants in the gross motor group had lower BMC at 18 months compared with noncompliant infants . These results indicate that BMC in infants is related to calcium intake , and we speculate that participation in a gross motor program during rapid bone growth may lead to reduced bone accretion in the presence of a moderate to moderately low calcium intake
Physical activity interventions were consistently ( > 60 % of studies ) associated with improved motor and cognitive development , and psychosocial and cardiometabolic health .
Across observational studies , physical activity was consistently associated with favourable motor development , fitness , and bone and skeletal health .
For intensity , light- and moderate-intensity physical activity were not consistently associated with any health indicators , whereas moderate- to vigorous-intensity , vigorous-intensity , and total physical activity were consistently favourably associated with multiple health indicators .
Across study design s , consistent favourable associations with health indicators were observed for a variety of types of physical activity , including active play , aerobic , dance , prone position ( infants ; ≤1 year ) , and structured/organized .
Apart from ≥30 min/day of the prone position for infants , the most favourable frequency and duration of physical activity was unclear .
However , more physical activity appeared better for health .
Conclusions Specific types of physical activity , total physical activity , and physical activity of at least moderate- to vigorous-intensity were consistently favourably associated with multiple health indicators .
Background Given the rapid development during the early years ( 0 - 4 years ) , an underst and ing of the health implication s of physical activity is needed .
The purpose of this systematic review was to examine the relationships between objective ly and subjectively measured physical activity and health indicators in the early years .