Currently, health authorities both nationally and internationally recommend 60 minutes of moderate-to-vigorous physical activity daily for children aged 6 to 17 years.
But is that really enough?
Researchers at the Norwegian School of Sport Sciences (NIH) have conducted a comprehensive review, analyzing 14 international follow-up studies to investigate the relationship between physical activity and sedentary behavior with various cardiovascular health markers.
The Largest Study to Date
Nearly 13,000 children and adolescents from 16 different countries across four continents were included in the study. No previous study of this scale has measured children's activity levels using motion sensors (accelerometers).
"This is the best and most comprehensive study conducted in this field to date," says Professor Ulf Ekelund, one of the most renowned researchers in public health and physical activity internationally.
The findings also show that the most important thing parents can do in relation to physical activity and sedentary time, is to ensure their children engage in activities that make them short of breath during the day.
- Moderate-to-vigorous physical activity (fast walking, active play, and activities that make you out of breath and sweaty) has a slight but favorable association with markers for cardiovascular health (such as insulin, LDL cholesterol, triglycerides, and an overall risk score).
- The researchers found no association between total sedentary time and a worse cardiovascular risk profile among youth.
- However, physical activity exceeding the current recommendation (60 minutes of at least moderate intensity per day) may be necessary to improve young people's cardiovascular risk markers.
"This suggests that sedentary behavior in itself is not a risk factor for cardiovascular health in children. The most important public health measure is to ensure that children raise their heart rate for some portion of the day, rather than focusing solely on the minutes they spend sitting," says Anders Husøy from the Department of Sports Medicine at NIH, one of the researchers behind the report.
The reason researchers believe the activity recommendation should be increased is that the study showed only the most active children had a lower likelihood of a higher cardiovascular risk score.
"Those in this group averaged 92.8 minutes of activity per day. This could suggest that the recommendation should be closer to 90 minutes per day," says Husøy.
Adjusting Activity Guidelines by Age
The established recommendation of 60 minutes per day was introduced in 1998. Ekelund believes it is high time for the World Health Organization (WHO) to update its guidelines.
Since 1998, more and far better studies have been conducted in this field.
"The established guidelines are largely based on older cross-sectional studies, and only three studies at the time included actual measurements of blood pressure and blood markers."
He also believes health authorities should consider separate activity recommendations for different age groups. The relationship between activity level and risk markers for cardiovascular health was strongest in the younger groups of children.
"Now I am speculating a bit, but I think the current recommendation for ages 6 to 17 years spans too wide an age range. I believe there should be separate recommendations for children aged 6 to 11–12 years and for adolescents," says Ekelund.
The researchers emphasize that more research is needed to draw definitive conclusions, partly because teenagers change rapidly in many ways.
The Group for Whom Activity Is Most Important
The study also observed a stronger relationship between physical activity and better cardiovascular health markers among those with the highest BMI.
"This indicates that physical activity is particularly beneficial for this group."
The researchers emphasize that this study only looked at a few of many health markers.
"This is, of course, just a small part of children's overall health. Physical activity has numerous other benefits for children that this study did not measure – such as improved cognitive function and learning, better mental health and well-being, stronger bones, and physical fitness," says Jakob Tarp, who is also part of the NIH research group behind the study.
The article has been translated using AI and quality-checked by NIH.