The purpose of the proposed study is to determine the effect of walking to school for one week on total physical activity and patterns of physical activity in third, fourth and fifth grade students.

Increasing children's physical activity has become an important public health concern. Active transportation (walking and bicycling) is one aspect of children's physical activity that has received little attention but may provide a means of increasing children's activity levels. Traveling to school is a common activity for most children in the United States. Due to this regularity, active transportation to school provides a possible way to incorporate an increase in children's moderate-to-vigorous physical activity into a routine activity.

Several "walk to school" programs have been implemented but it is not known if the physical activity levels of children walking to school are greater than those that get chauffeured or bused. Theoretically, moderate intensity activity should be greater in the walkers compared to others. This difference should be in proportion to the duration of the walk to and from school; determined by how far the child lives from the school. However, more activity in the morning may have an impact on activity levels later in the day. Therefore, differences in daily activity patterns in addition to total activity need to be considered.

Comparison(s): Following a baseline week, the physical activity of students randomized to a Walk to School group will be compared to those randomized to a Control group, who will continue to be driven to school.

Inclusion Criteria:

• 3rd, 4th, or 5th grade at participating school

Exclusion Criteria:

• Currently walking or bicycling to school at least 4 times per week
• Physical or mental disability that would prevent walking to school under adult supervision.