" Moreover, when Ingunn Fjørtoft, a professor at Telemark University in Porsgrunn, Norway, compared five- to seven-year-olds at three different kindergartens in Norway, she found that those who played in the forest daily had significantly better balance and coordination than children who only played on a traditional playground. Once again, the reason is believed to be that children are faced with more complex physical challenges in nature, and that this boosts their motor skills and overall fitness. "

― Linda Åkeson McGurk , There's No Such Thing as Bad Weather: A Scandinavian Mom's Secrets for Raising Healthy, Resilient, and Confident Kids (from Friluftsliv to Hygge)