Objective physical activity of Filipino youth stratified for commuting mode to school

Purpose: The Cebu Longitudinal Health and Nutrition Survey included self-report measures and objective measures (Caltrac accelerometer) of Filipino adolescent (ages 14-16) physical activity (PA) in 1998-99. The purpose of this subanalysis was to compare objectively monitored PA of adolescents who differed by their self-reported habitual commuting mode to school, specifically commuting by walking, motorized transport, or a combination of the two. Methods: Descriptive analysis included the proportion of adolescents who reported commuting to school by the different modes, participating in sport/exercise during or after school, or currently working. ANCOVA was used to estimate and compare adjusted mean Caltrac-derived energy expenditure (kcal(.)d(-1)) by commuting mode for each gender. Covariates were age, weight, and height. Results: The analysis sample of 1518 Filipino adolescents included 691 male (BMI = 18.5 +/- 2.5) and 827 female subjects (BMI = 18.7 +/- 2.3). A total of 323 male subjects (46.8% of all male subjects) walked to school, 160 (23.2%) took motorized transport, and 208 (30.0%) used a combination of the two modes. The corresponding values for female subjects were 303 (36.6%), 177 (21.4%), and 347 (42.0%). The absolute difference in Caltrac-derived energy expenditure that appeared to be due to active commuting was 44.2 kcal(.)d(-1) for Filipino male adolescents and 33.2 kcal(.)d(-1) for female adolescents. These differences between commuting modes could not be explained by participation in sport/exercise or by current employment. Conclusions: Assuming 200 school days in a year, the difference in energy expended due to active commuting translates to a 8840 kcal and 6640 kcal in male and female subjects, respectively. For those youth who commute to school by motorized transport a yearly positive energy balance (i.e., weight gain) of 2-3 lb would be anticipated, all other things being held constant.