Childhood obesity has become an epidemic and is emerging as a public health crisis in the United States. The rate of obesity among U.S. preschool children alone has doubled during the past 30 years. The increasing prevalence among this age group indicates that prevention efforts need to begin during the preschool years.

PURPOSE: To describe habitual physical activity behavior of 3- and 4-year old children in a large Midwestern Metropolitan area.

METHODS: Participants were 42 children (15 boys and 27 girls) randomly selected from two day care centers, one serving mostly African American preschoolers and one serving mostly Caucasian children. Habitual physical activity was measured using the GT1M accelerometer (ActiGraph, Pensacola, FL). Parents of the participants were asked to fit the accelerometers on their children in the early morning and remove them at night for a period of six consecutive days. The GT1M produces output in activity counts per unit of time, which is considered in “raw” form (counts per minute (cpm)) as a valid index of total “volume” of physical activity (Nillson et al., 2002).

RESULTS: The mean duration of accelerometry in the preschoolers was 58.21 hours over 6 days (SD=19.7). Based on age-specific cutoffs, the preschoolers spent 75.4% of their time in sedentary behavior (?1100 cpm), 21.6% in light physical activity (1100-3200 cpm), and 3% in moderate to vigorous physical activity (MVPA) (?3200 cpm). Using paired t tests, we found that the preschoolers spent a greater percentage of time in both light (t=3.29, p<.01) and MVPA (t=2.57, p<.01) in schools than they did outside of schools. No significant differences were found in out of school activities between week days and the weekend. The one-way analyses of variance revealed the influence of site on in-school physical activity. The percentage of time spent in MVPA was significantly higher in the school serving mostly Caucasian children than the one serving mostly African American (F=4.67, p<.05).

CONCLUSION: Our findings report that overall physical activity levels of the preschoolers are below the National guidelines (NASPE, 2002). Because of the role school setting plays in physical activity involvement, instituting an efficient physical education curriculum in day care centers can be an important part of fighting the overweight and obesity crisis.