👤 David Burgner

There is increasing interest in the importance of patterns of accumulation and overall daily time-use composition of physical activity (PA) and sedentary time (SED) for children's cardiometabolic health. This study examined cross-sectional associations between the time-use composition of PA and SED patterns with cardiometabolic risk factors in 4-year-olds. Data were drawn from the Barwon Infant Study 4-year review (n = 467). Accelerometer data were classified into short (≤ 1-minute) and long (> 1-min) SED, light-, moderate-, and vigorous-intensity PA (LPA, MPA, VPA) bouts. A waking time-use composition of eight distinct components (total volumes plus short and long bouts of SED, LPA MPA, VPA) was constructed using compositional data analysis. Linear mixed models examined associations between composition patterns and body mass index (BMI), percent body fat, triceps and subscapular skinfold thickness, blood pressure, heart rate, carotid-femoral pulse wave velocity, and aortic and carotid intima-media thickness. Adjusted models indicated a higher ratio of long versus short LPA bouts was associated with higher z-BMI (β = 1.69, SE = 0.83, p = 0.04), percent body fat (β = 10.72, SE = 3.71, p = 0.004), and z-triceps (β = 1.90, SE = 0.93, p = 0.04). A higher ratio of long versus short MPA bouts was associated with lower z-BMI (β = - 0.99, SE = 0.46, p = 0.03) and percent body fat (β = - 4.63, SE = 1.93, p = 0.02). A higher total volume of MPA versus VPA was associated with higher percent body fat (β = 4.07, SE = 1.63, p = 0.01) and z-triceps (β = 1.05, SE = 0.43, p = 0.01). Other outcomes showed no associations (p ≥   0.05). In preschoolers, accumulating LPA in shorter bursts, MPA in longer bursts, and maintaining a higher proportion of VPA may support healthier adiposity profiles. These findings underscore the importance of minimizing prolonged sedentary time and encouraging sustained, high-intensity PA from early childhood. Show less