Relationship Between Daily Physical Activity And Neighborhood Environment Among Japanese Preschool Children

Abstract

Recent studies have shown the significance of environment as a determinant of physical activity in both children and adults. However, few such studies have specifically looked at Japanese children. Young children do not usually engage in prolonged exercise. Therefore, it is important to assess environmental determinants of physical activity in young children by objective methods such as the use of accelerometers. PURPOSE: The aim of this study was to examine the relationship between daily physical activity and perceived neighborhood environment among Japanese preschoolers. METHODS: Physical activity was assessed using a triaxial accelerometer (ActivTracer, GMS) for 6 consecutive days, including weekdays and weekends, in 361 four- to six-year-old Japanese children attending kindergartens or nursery schools. Subjects were asked to wear these devices at all times except when it was not possible, such as while dressing and bathing. Synthetic activity counts were recorded every 1 min by the ActivTracer, and the PAR (physical activity ratio), a multiple of basal metabolic rate, was estimated. When synthetic activity counts were in the range corresponding to medium-intensity activity, classification criteria using the vertical/horizontal counts ratio were used to discriminate between different types of medium-intensity activity, because the PARs for some medium-intensity activities (i.e., non-locomotive activities) can be underestimated (Tanaka et al., Obesity, 2007). Neighborhood environment was evaluated using a questionnaire. Data were collected between 2006 and 2008. RESULTS: Mean time spent in moderate-to-vigorous physical activity (MVPA) and physical activity level (PAL) were 99 (±30) min/day and 1.54 (±0.08), respectively. There were significant correlations between MVPA time and low crime rate and the presence of nature in the neighborhood after adjustment for age, sex, height, and weight. The correlation between minutes of PAR≥4 and the presence of hills was also significant. CONCLUSIONS: These findings indicate that time spent in MVPA and PAR≥4 are associated with specific neighborhood environmental attributes among preschoolers.Supported by Health Sciences Research Grants (Research on Health Science) from the Ministry of Health, Labor and Welfare (to C. Tanaka).