 is one way of doing that. The study also found that walking to school added an extra 15 to 20 minutes of overall physical activity to children's days, yet the proportion of kids who walk to school has dropped from 40% a few decades ago to 15% now. So building schools closer to students' homes, improving pedestrian safety, and utilizing drop-off zones when the distance to school is too far, they could have meaningful impacts on their overall physical activity and health, Carlson said.