Results Physical activity was associated with numerous health benefits .
The dose-response relations observed in observational studies indicate that the more physical activity , the greater the health benefit .
Results from experimental studies indicate that even modest amounts of physical activity can have health benefits in high-risk youngsters ( e.g. , obese ) .
Vigorous intensity activities may provide even greater benefit .
Aerobic-based activities had the greatest health benefit , other than for bone health , in which case high-impact weight bearing activities were required .
Some of the health benefits can be achieved through an average of 30 minutes per day . [
Level 2 , Grade A ] .
Background The purpose was to : 1 ) perform a systematic review of studies examining the relation between physical activity , fitness , and health in school-aged children and youth , and 2 ) make recommendations based on the findings .
Does previous participation in high-impact training result in residual bone gain in growing girls? One year follow-up of a 9-month jumping intervention.
The skeletal response to exercise and training on bone is exceptionally good during the growing years . However , it is not known whether the benefit of training on bone is maintained after the training . This 20-month follow-up study assessed the effect of a 9-month jumping intervention on bone gain and physical performance in 99 girls ( mean age 12.5 + /- 1.5 years at the beginning of the study ) one year after the end of the intervention . Both bone mineral content ( BMC ) , by dual energy X-ray absorptiometry ( DXA ) at the lumbar spine and proximal femur , and physical performance parameters ( st and ing long jump , leg extension strength , and shuttle run tests ) were measured at baseline and at 20 months . A multivariate regression analysis was first used to determine the best predictors of the BMC accrual by time . Analysis showed that age at baseline and square of age , changes in height and weight , and pubertal development into Tanner stages 4 and 5 during the follow-up explained the majority of the BMC gain . Then , the effect of participation in the 9-month exercise intervention on BMC accrual and physical performance was analysed adding this variable ( participation : yes/no ) into the model . The regression analysis showed that the trainees ( N = 50 ) had 4.9 % ( 95 % CI , 0.9 % to 8.8 % , p = 0.017 ) greater BMC increase in the lumbar spine than the controls ( N = 49 ) . The mean 20-month BMC increase in the lumbar spine was 28 % ( SD 19 ) in the trainees compared to 22 % ( 12 ) increase in the controls . In the proximal femur , the trend was similar but the obtained 2 to 3 % higher BMC accrual in the trainees ( compared to that in controls ) were statistically insignificant . Among the performance variables , using the same model that best predicted the BMC accrual , the only statistically significant between-groups difference , in favour of the trainees , was the improvement in the st and ing long jump test ( 6.4 % , 95 % CI , 2.3 % to 10.4 % , p = 0.002 ) . Improvements in the leg extension strength and shuttle run tests showed no between-groups difference . In conclusion , although the greatest proportion of bone mineral accrual in growing girls is attributable to growth , an additional bone gain achieved by jumping training is maintained at the lumbar spine at least a year after the end of the training
Results Physical activity was associated with numerous health benefits .
The dose-response relations observed in observational studies indicate that the more physical activity , the greater the health benefit .
Results from experimental studies indicate that even modest amounts of physical activity can have health benefits in high-risk youngsters ( e.g. , obese ) .
Vigorous intensity activities may provide even greater benefit .
Aerobic-based activities had the greatest health benefit , other than for bone health , in which case high-impact weight bearing activities were required .
Some of the health benefits can be achieved through an average of 30 minutes per day . [
Level 2 , Grade A ] .
Background The purpose was to : 1 ) perform a systematic review of studies examining the relation between physical activity , fitness , and health in school-aged children and youth , and 2 ) make recommendations based on the findings .