The longitudinal research included 2,513 children from the University of Bristol's Children of the 90s cohort, monitored from age 11 to 24. At the beginning of the study, participants averaged six hours of sedentary behavior, six hours of LPA, and around 55 minutes of moderate-to-vigorous physical activity (MVPA) daily. By young adulthood, sedentary behavior increased to nine hours per day, while LPA dropped to three hours, and MVPA averaged about 50 minutes per day.

Initial average blood pressure recorded in childhood was 106/56 mmHg, rising to 117/67 mmHg by adulthood due to natural growth. However, persistent sedentary time contributed to an extra 4 mmHg increase in systolic pressure. Conversely, children engaging in consistent LPA exhibited a 3 mmHg reduction in final systolic pressure, while MVPA did not show a blood pressure-lowering effect.

"Furthermore, when 10 minutes of every sedentary hour was replaced with LPA from childhood through young adulthood in a simulation model, systolic blood pressure dropped by 3 mmHg and diastolic by 2 mmHg," explained Andrew Agbaje, associate professor of Clinical Epidemiology and Child Health at the University of Eastern Finland. He highlighted that a 5 mmHg reduction in systolic pressure could reduce heart attack and stroke risks by 10% in adults.

This extensive study, which involved repeated blood pressure, movement, and metabolic measurements at ages 11, 15, and 24, is the most comprehensive of its kind. It also considered factors like cholesterol levels, heart rate, body composition, socioeconomic status, and smoking habits.

"We have previously shown that high blood pressure in adolescence elevates the risk of early cardiac damage in young adulthood. Identifying sedentariness as a risk factor for increased blood pressure with LPA as a potential countermeasure has important public health implications. MVPA trials in youth have not lowered blood pressure, possibly due to MVPA's role in increasing muscle mass, which might elevate pressure," Agbaje noted.

The World Health Organization predicts that by 2030, 500 million new cases of diseases related to physical inactivity could emerge, with hypertension playing a significant role. Agbaje emphasized the necessity of at least three hours of LPA daily to mitigate and reverse high blood pressure. "Parents, pediatricians, and policymakers must encourage children to stay active with activities like walking, household chores, swimming, and cycling," he urged.