Physical activity in children plays a vital role in preventing the development of risk factors for cardiovascular disease (CVD), however the amount of physical activity that young children require is unclear. Current recommendations are that children should engage in 60 minutes of physical activity (of at least moderate intensity) per day, but much of the existing research focuses on older children. New research published in BMC Medicine by Luis Moreno from the University of Zaragoza, Spain and colleagues suggests that, although this may be adequate for girls aged six to nine years, boys in this age group may require more physical activity each day.
Using data on 3,019 children from the ‘Identification and prevention of Dietary- and lifestyle-induced health Effects In Children and infantS’ (IDEFICS) study, which was conducted across nine European countries, Moreno and colleagues investigated the association between objectively-measured physical activity and clustered CVD risk factors in children to provide evidence for gender-specific recommendations. They analysed the relationship between physical activity and CVD risk factors using data on total triglycerides, total cholesterol, HDL-c, glucose, insulin, systolic blood pressure, two skinfold thickness measurements, physical activity intensities (collected by accelerometer) and confounding factors. The data was analysed separately for two age groups – two to six and six to nine years of age.
The results showed an inverse relationship between physical activity and clustered CVD risk factor scores for boys and girls aged six to nine. In the younger age group, a weaker inverse relationship was found for boys but there was no significant relationship for girls. In the older age group, children in the most active quintile spent a mean time of 85 minutes (boys) and 66 minutes (girls) per day doing moderate to vigorous physical activity. Based on these findings, they suggest that the current recommendations (of 60 minutes) may be an underestimation for boys. Instead, they recommend that for boys aged six to nine years, 85 minutes per day of physical activity of at least moderate intensity may be a more appropriate cut off to ensure a lower CVD risk factor score than current recommendations. For both boys and girls, approximately 20 minutes of this should be vigorous physical activity.
This is the first study to objectively analyse the association between physical activity and clustered CVD risk factors in a large sample of children between the ages of two and nine years of age, a younger age group than in previous studies on which the current recommendations have been based. Moreno and colleagues show evidence of clustering of CVD risk factors in young children and provide insights into the physical activity requirements of this age group for physicians and other healthcare workers.
Physical activity is important to prevent clustering of CVD risk factors in children aged six to nine years, and although evidence into the role of physical activity in children under six years is less consistent, this study indicates that physical activity may also be a preventative tool in younger children.