Background:
Smart growth (SG) urban planning strategies (e.g., preservation of open space, integration of mixed land uses, establishment of compact building design, creation of walkable neighborhoods) may increase physical activity and prevent obesity in children. However, little is known about whether and how frequently children living in SG communities actually use the environmental features that are available. Lack of awareness of opportunities, lack of time, safety concerns, and other factors may serve as barriers to use. To address this question, research is needed on whether the types of settings used for physical activity differ between children living in SG as compared to traditionally designed communities. Such data present methodological challenges, which can be overcome through real-time data capture methods such as Ecological Momentary Assessment (EMA).
Objectives:
The objectives of this study were to determine (1) whether the physical activity contexts of children living in a SG community differ from children living in conventionally-designed communities (control); and (2) whether 6-month changes in physical activity contexts lead to greater increases in physical activity for children living in the SG vs. control communities.
Methods:
Participants included 61 children who had recently moved to a SG community (median time in residence = 12 months) in Southern California and 59 children living in nearby control communities (whose families had considered moving to the SG community). The groups were comparable in age (M = 11.0 years, range 9-13 years), gender, (52% male), income (25% less than $45,000/yr), ethnicity, (32% Hispanic) and weight status (38% at risk/overweight). Children participated in two EMA waves separated by about 6 months. Each wave consisted of four consecutive days (Fri. at 4pm to Mon. at 8:30pm) of EMA during non-school leisure time. Each EMA survey was prompted at a random time within one of the 20 two-hour blocks occurring across the four days. Answering with push-bottoms to electronic questions on the mobile phone, children reported their primary activity (e.g. active play/sports/exercise, watching TV/movies), social company (e.g., family, friends, alone), physical location (e.g., home, outdoors), and other physical contextual features (e.g., perceived safety, traffic, vegetation, distance from home). Children simultaneously wore an Actigraph accelerometer during the EMA monitoring. Moderate-to-vigorous physical activity (MVPA) was defined as activity with intensity ≥ 4 Metabolic Equivalents (METs) (1,952 counts/min.). Only children with at least one EMA report of active play/sports/exercise at either time point were included in the analyses. Multilevel multinomial logistic regression analyses tested the main effects and interactions for group (SG vs. control) and time (1 vs. 2) predicting the likelihood of (1) physical activity occurring in each context and (2) achieving recommended levels of MVPA (i.e., 60+ minutes per day).
Results:
Ninety-seven children at time 1 and 76 children at time 2 had at least one report of active play/sports/exercise. Among SG children, the proportion of physical activity bouts reported at home (indoors) decreased between time 1 (28%) and time 2 (13%); whereas the proportion of home-based physical activity did not change in the control group (Adj. Wald F = 10.58, p < .001). As compared to the control group, SG children engaged in a greater proportion of physical activity bouts with friends (19% vs. 9%) and a smaller proportion with family members (25% vs. 42%) (Adj. Wald F = 3.0, p = .03) at both time points. Also, SG children engaged in a greater proportion of physical activity bouts a few blocks from home (40% vs. 18%) (Adj. Wald F = 4.88, p = .009) and traveled to a greater proportion of physical activity bouts by walking (33% vs. 15%) (Adj. Wald F = 2.39, p = .065) as compared to the control group at both time points. A greater proportion of SG children (18%) vs. control (11%) met physical activity recommendations at both time points, but neither this group difference nor the group x time interaction were statistically significant.
Conclusions:
Children who had recently moved to a SG community were more likely to be physically active with friends and within a few blocks from home, and less likely to engage physical activity with family members than children living in traditionally designed communities. A greater proportion of children moving to the SG community traveled to physical activity locations by walking than children from traditional communities. However, these group differences did not lead to significantly greater overall physical activity among children living in the SG community. With the exception of home-based physical activity, the physical activity contexts of children who had recently moved to the SG community did not change across the six months of the study. These findings indicate that children might begin to alter their physical activity contexts immediately after moving to SG communities (i.e., prior to enrolling in the study). Yet more time may be necessary for these changes to impact overall physical activity.
Support:
Active Living Research #RWJF 65837 and National Cancer Institute #R01-CA-123243.
