Being active in nature makes children healthier. Children living within a mile of a park are more likely to have higher levels of physical activity. Exposure to nature can reduce stress level by as much as 28%in children. There are more than 20,000 thousand parks and 11,000 playgrounds totaling over 1.5 million acres in cities across the U.S. Children living within 2/3 miles of a park with a playground can be 5 times more likely to have a healthy weight. Even a 20-minute walk in nature can help children with attention deficit hyperactivity disorder concentrate well. AAP recommends that children should be physically active for at least 60 minutes throughout a day and limit time with electronic media to 2 hours per day. Parents, friends, and family are the most influential to youth participation to outdoor activities.