Participation in physical activity has declined dramatically among U.S. youth, especially among girls. Little is known about the opportunities for increasing participation in moderate-to-vigorous physical activity (MVPA) among adolescents before school, although active commuting to school has been identified as a potential source of physical activity.
PURPOSE: To examine how travel by walking before school contributes to total physical activity of adolescent girls.
METHODS: A total of 1596 healthy 6th grade girls, age 11–12 years, were recruited from a random sample of 2160 girls from 36 schools participating in the Trial of Activity in Adolescent Girls (TAAG). Age, ethnicity, and socioeconomic status were obtained from the girls by questionnaire. Each participant wore an Actigraph accelerometer for 6 days and completed a modified version of the 3-Day Physical Activity Recall (3DPAR). Participants were classified as walkers if they reported travel by walking” before school on one or more weekdays on the 3DPAR. Linear mixed models were used to evaluate the influence of “travel by walking” before school on daily physical activity, controlling for clustering effects by study center.
RESULTS: 14% of participants reported before school travel by walking; the remaining before school activities were reported by 1% or fewer participants (e.g. walking for exercise, running/jogging, travel by bicycle). Girls who reported “travel by walking” had 4.3 more minutes (95% confidence interval [CI], 2.4–6.2) of total activity (light, moderate, and vigorous) and 1.7 more minutes spent in MVPA (>1500 counts/ 30s) compared to non-walkers before school (95% CI, 1.4–2.0). Walkers expended 87 kJ (95% CI, 50–123) more energy before school than non-walkers. The longest period of continuous MVPA (> a slow walk) before school was 10 minutes for walkers and 5 minutes for non-walkers. Girls who reported “travel by walking” before school had 11 more minutes of total activity for the day compared to non-walkers (95% CI, 2.3–20.5), and 3.1 more minutes of MVPA (95% CI, 1.3–24.9).
CONCLUSIONS: This study reveals a potential opportunity for increasing the activity level of adolescent girls through interventions designed to promote active travel before school.