Linking 23 physical activity intensity levels to health-related quality of life in 10-year-old children

This study analyzed cross-sectional baseline data from the ASK study, a randomized controlled trial. The Kidscreen-27 questionnaire assessed HRQoL, with the "physical well-being" domain as the primary outcome. Physical activity levels were measured using ActiGraph GT3X + accelerometers, capturing 23 intensity bands ranging from 0 to 99 to ≥ 10,000 counts per minute (cpm). Partial least squares regression analysis was used to explore the associations between physical activity and HRQoL. The study included 722 fifth-grade children (mean age 10.2 ± 0.3 years, mean waist circumference 61.8 ± 7.4 cm, 51% male). In the overall cohort, physical activity accounted for 5.23% of the variance in physical well-being, with 2.03% for girls and 9.06% for boys. Among boys with overweight/obesity, the explained variance increased to 20.03%, compared to 8.63% for those without. For girls, no association was observed for those without overweight/obesity, whereas 8.93% of the variance was explained for those with overweight/obesity. High-intensity physical activity (6000-7000 cpm) showed the strongest associations, though positive relationships were evident across all intensity levels.