Children need more physical activity
A recent study lead by Professor Lars Bo Andersen at Norwegian School of Sport Sciences concludes that physical activity levels among school children should be higher than the current international guidelines.
Published: 8/1/2006
The study, which was published in the July edition of
The Lancet, claims that the recommended level of physical activity among school children should be raised from one hour to one and a half hour.
Professor Bo Andersen at
Department of Sport Medicine lead a cross-sectional study of 1732 randomly selected 9-year-old and 15-year-old school children from Denmark, Estonia and Portugal.
The scope of the study was to find any relation between physical activity and clustered cardiovascular risk among children. The findings showed that the least active children had a three times as high cardiovascular risk compared to the 20% most active children.
- Insufficient activity level
The study has attracted international attention because of its advise to raise the level of recommended daily physical activity among children.
- Despite more children participating in leisure-time sports, the epidemics of metabolic disorders and obesity continue to occur. Clustering of cardiovascular risk factors starts in early childhood but increased physical activity can reduce the risk of this clustering. Today’s guidelines for physical activity in children are not sufficient in order to prevent the risk of cardiovascular diseases, Bo Andersen says.
- Achieving 90 minutes of daily activity might be necessary for children to prevent insulin resistance, which seems to be the central feature of the clustering of cardiovascular disease risk factors, Bo Andersen continues.
Problems with previous studies
The study also raises questions about previous studies regarding physical activity and health in children.
First, previous studies have relied on subjective measures and feedback from the children about their habitual physical activity rather than objective and more accurate measures.
Secondly, many studies have only analysed the relation between physical activity and single cardiovascular disease risk factors, rather than a clustering of such factors.
- Our aims were to examine different measures of physical activity with clustering of cardiovascular disease risk factors and to examine whether a dose-response relation exists from which guidelines for young people can be obtained, Bo Andersen says
Objectively measured activities
In his study, physical activity was assessed with an accelerometer. This accelerometer measured the vertical acceleration of body movement. Physical activity was monitored for four consecutive days and instruments were attached tightly at the hip.
Minute-by-minute data were stored as counts in memory and subsequently downloaded to a computer.
- The main strengths of this study were the availability of measures of insulin resistance and other cardiovascular risk factors in a large population of children, together with details of objectively measured physical activity, Professor Andersen says.