Results There was consistent evidence for a positive association between MF and physical activity .
For both MF components , there was support for objective ly measured physical activity , particularly for activity of vigorous intensity .
Sports participation was also consistently linked with both MF components , whereas the association with active transport was inconsistent .
For both MF components , associations with sedentary behaviors were inconsistent irrespective of measurement method , and the association between MF and sleep was considered uncertain .
Conclusions The available evidence supports a link between MF and physical activity , particularly for vigorous intensity activity and organized sports participation .
Background Muscular fitness ( MF ) is considered a powerful marker of health , but the extent to which common health behaviors are associated with MF during childhood and adolescence is currently unclear .
Objective We conducted a systematic review of studies investigating associations between MF ( i.e. , strength/power , local muscular endurance ) and physical activity , sedentary behaviors , and sleep in children and adolescents .
Weight status, physical activity, and fitness among third-grade rural children.
BACKGROUND Rural children are at a particular high risk for obesity . Given the importance of exercise in obesity and chronic disease prevention , this study evaluated the level and relationship between physical activity and fitness in a sample of rural third grade rs . The second purpose of the study was to determine potential differences in physical activity and fitness level by weight status in this sample . METHODS Twelve schools participating in a multidisciplinary research project were r and omly selected for the study . Body mass index-for-age percentile , the modified Self-administered Physical Activity Checklist  , and the FITNESSGRAM battery tests were utilized to determine children 's weight status , physical activity , and fitness level , respectively . RESULTS Thirty-eight percent of the 237 participating children ( 9.2 ± 0.4 years ) were overweight or obese . Nearly 15 % were extremely obese . Children spent 91.8 ± 83.8 and 32.2 ± 47.7 minutes in moderate- and vigorous-intensity activities . Obese children spent less time in moderate-intensity activity ( p < .01 ) and combined moderate- and vigorous-intensity activity more than other children ( p < .05 ) . Forty-three percent of all children failed to meet the fitness st and ard for muscular strength and 36 % failed to meet it for flexibility . CONCLUSIONS Rural children in this sample had higher rates of obesity compared to the national average ; they had poor fitness and 30 % failed to meet the minimum physical activity recommendations on the previous day . Future interventions should focus on increasing physical activity , especially of moderate-intensity , and improving physical fitness in order to reduce obesity and decrease the risk of future chronic diseases in this high-risk population
Results There was consistent evidence for a positive association between MF and physical activity .
For both MF components , there was support for objective ly measured physical activity , particularly for activity of vigorous intensity .
Sports participation was also consistently linked with both MF components , whereas the association with active transport was inconsistent .
For both MF components , associations with sedentary behaviors were inconsistent irrespective of measurement method , and the association between MF and sleep was considered uncertain .
Conclusions The available evidence supports a link between MF and physical activity , particularly for vigorous intensity activity and organized sports participation .
Background Muscular fitness ( MF ) is considered a powerful marker of health , but the extent to which common health behaviors are associated with MF during childhood and adolescence is currently unclear .
Objective We conducted a systematic review of studies investigating associations between MF ( i.e. , strength/power , local muscular endurance ) and physical activity , sedentary behaviors , and sleep in children and adolescents .