Introduction Early childhood physical activity and sedentary behavior influence long-term health, yet evidence on interventions targeting how these behaviors are accumulated – rather than just total time – is limited. This study examined the impact of a parent-focused early childhood obesity prevention intervention on preschoolers’ physical activity and sedentary behavior patterns. Methods This study is a secondary analysis of data from the Melbourne Infant Feeding, Activity and Nutrition Trial InFANT clustered randomized control trial (2008–2013). Physical activity and sedentary behavior data were gathered using ActiGraph™ GT1M accelerometers. To capture insights beyond total time and examine accumulation patterns, the duration and frequency of sedentary bouts ≤100 counts per minute (cpm), light-intensity physical activity (101–1,680 cpm) bouts, and moderate- to vigorous-intensity physical activity (≥1,681 cpm) bouts, each lasting ≥1 min, as well as the total number of sedentary breaks, were calculated at each time point. The ≥1 min cut-offs for bout durations were defined based on the medians observed in this sample (0.50 min for sedentary, 0.47 min for light-, 0.25 min for moderate- to vigorous-intensity physical activity). Multilevel regression analyses were fitted to examine intervention effects at 19 months (T3), and 3.5 (T4) and 5 (T5) years of age. Results In total, 296, 144 and 140 participants had valid accelerometry data and were included in the analytical sample at T3, T4 and T5, respectively. The intervention had a significant and beneficial effect on the total amount of sedentary breaks at 3.5 ( β 95%CI = 10.92.98,18.91) and 5 years ( β [95%CI = 7.94[0.03,15.86). The intervention effects on all other outcomes were small and not significant. Discussion Whilst only effects on sedentary breaks were observed, this study suggests that interventions may impact accumulation patterns in children under five. Trial registration The Melbourne Infant Feeding, Activity and Nutrition Trial was registered with the International Standard Randomized Controlled Trial Number Register (ISRCTN81847050; 7/11/2007).
Boerdijk et al. (Wed,) studied this question.