Temporal trends of physical activity and sedentary behavior among Greek school-age children: A comparison of two cross-sectional cohorts

Many studies have highlighted the importance of physical activity in fostering health and preventing diseases among children and adolescents. Concurrently, mounting evidence underscores the detrimental health effects associated with high levels of sedentary behavior in children. Understanding the temporal changes in childrens physical activity and sedentary behavior patterns is crucial for identifying evolving contexts that may require tailored interventions. This study investigates gender-specific changes in accelerometer-measured physical activity and sedentary behavior patterns among 8-11-year-old children from the same region of Greece, juxtaposing data from two different time frames (2014 and 2021). The cohort comprised 144 school-age children, with 68 participants from the 2014 cohort and 76 from the 2021 cohort. Physical activity and sedentary time were tracked using hip-worn accelerometers (Actigraph GT3X+). Participants were directed to wear the device continuously for seven consecutive days during their waking hours. Vector magnitude counts per minute and daily step counts were used to assess the total volume of physical activity, and Freedson population-specific cut-points for children were applied to classify physical activity levels. Factorial ANOVA models were conducted independently for each physical activity metric to explore discrepancies between the two measurement periods for each gender. The studys findings revealed a temporal trend indicating a decline in light physical activity alongside a significant increase in the percentage of total daily sedentary behavior. However, steps per day, counts per minute, and levels of moderate-to-vigorous physical activity remained relatively stable and did not significantly change. The average duration of sedentary bouts significantly increased only among girls. The results also indicated a slight increase from 2014 to 2021 regarding the proportion of children meeting physical activity recommendations. Modern children allocate less time to light physical activity and more time to sedentary pursuits, significantly increasing uninterrupted sedentary periods during the day. Our results underscore the need for tailored initiatives to promote and enable physical activity, particularly among girls. Addressing barriers and fostering inclusive opportunities is imperative to empower all children to adopt active and healthy lifestyles.