Children are not immune to the bad health effects of too much time sitting.
A study shows that spending more than six hours a day sedentary during childhood through young adulthood can lead to a significant increase in systolic (the “top number”) blood pressure.
The research, conducted by the Universities of Bristol and Exeter in the UK, along with the University of Eastern Finland, suggests that light physical activity can help offset this increase in blood pressure.
How the Study Was Done
The study followed 2,513 children and young adults from the University of Bristol’s “Children of the 90s” cohort from ages 11 to 24.
At the beginning of the study, the children were sedentary for about six hours per day, engaged in six hours of light physical activity and participated in around 55 minutes of moderate-to-vigorous physical activity daily.
By the time they reached young adulthood, sedentary time had increased to an average of nine hours per day, while light exercise decreased to three hours, and moderate-to-vigorous remained nearly the same.
The findings show that systolic blood pressure increased from an average of 106 mmHg in childhood to 117 mmHg by young adulthood, a typical trend due to natural development.
However, the study found that the rise in systolic blood pressure was 4 mmHg higher for those who spent more than six hours a day sedentary.
Engaging in light activity during the study period helped to mitigate this increase by lowering systolic blood pressure by 3 mmHg.
Interestingly, medium or vigorous activity did not have the same effect on blood pressure.
Takeaways
One of the key takeaways from the study was that small changes in sedentary behavior can have meaningful effects on blood pressure.
When researchers simulated replacing just 10 minutes of sedentary time each hour with an equal amount of light activity, they found a reduction in systolic blood pressure by 3 mmHg and diastolic blood pressure by 2 mmHg.
This is important because even small reductions in blood pressure can have significant health benefits.
For instance, a 5 mmHg decrease in systolic blood pressure has been shown to reduce the risk of heart attack and stroke by 10%.
The study also notes that light physical activity — such as walking, swimming or cycling —was key to reducing blood pressure.
Oddly, more intense activity such as running did not appear to lower blood pressure in the same way.
Researchers suggest this may be due to the fact that intense exercise can increase muscle mass, which in turn could contribute to a physiological rise in blood pressure.
This study is the largest and longest to track the relationship between physical activity, sedentary behavior and blood pressure in youth.
It tracked various factors including blood pressure, sedentary time, light and moderate/vigorous activity, cholesterol levels, glucose and other health markers, while also considering heart rate, socioeconomic status and family history of cardiovascular disease.
Dr. Andrew Agbaje, an associate professor at the University of Eastern Finland and the lead author of the study, points out that earlier research had shown a link between elevated blood pressure and an increased risk of early cardiac damage.
This study further supports the idea that sedentary behavior contributes to high blood pressure (hypertension), while light exercise serves as an effective strategy to combat this.
Get Your Kids Moving More
Getting children to move more can be fun and easy with a little creativity.
Encourage active play by organizing games like tag, hide-and-seek or dance parties at home.
Outdoor activities like biking, hiking or visiting a playground also get them moving.
Limit screen time and replace it with family walks or trips to the park.
Make physical activity a social event by inviting friends or siblings to join in.
Simple tasks like helping with chores or gardening can also keep kids active.
