Independent mobility and physical activity among children residing in an ultra-dense metropolis

Objectives: Independent mobility (IM), which is defined as the freedom of children moving without adult supervision, has been found to be positively associated with physical activity (PA). This study explored IM by sociodemographic factors and type of neighborhoods and its association with PA among children in Hong Kong.

Methods: A convenience sample of 330 children aged 8–12 years and their parents was recruited. The children wore an ActiGraph accelerometer for eight consecutive days to measure PA and sedentary time (ST). Parents reported parents’ license and children self-reported their actual mobility. Generalized estimating equations were conducted to examine the associations of IM with sociodemographics (e.g., children’s age, sex, body weight status, parents’ age, sex, maternal education) and type of neighborhood. Linear mixed models were performed to determine the associations of IM with PA and ST.

Results: Valid data from 296 children (8.8±0.6 years old, 42.2 % boys) were included in analysis. Children residing in sprawl and rural areas had greater parents’ license and actual mobility than those in urban areas. Greater parents’ license was associated with more moderate-to-vigorous intensity PA (MVPA) on weekend days (β=1.33, 95% CI: 0.15–2.51), while children’s actual mobility was positively associated with MVPA on weekdays (β=1.14, 95% CI: 0.10–2.18).

Conclusions: In densely populated metropolis, children living in highly urbanized areas with higher SES experienced reduced parental license and actual mobility compared to their peers in less affluent neighborhoods, irrespective of the level of urbanization.