The American Academy of Pediatrics (AAP) recently issued a position statement emphasizing the importance of play in promoting healthy development, particularly in children aged 0 to 6 years.1 Whereas this play may be guided at first by parents, as children get older their free play becomes even more important. The benefits of such play are well documented, yet the benefits of exposure to the natural environment are less well studied in the medical literature. However, recent work in the fields of Psychology, Public Health, and Urban and Environmental Studies have shown a variety of physical and mental health benefits related to exposure to and interaction with outdoor green spaces.2
One way to combine the benefits of these areas is for pediatricians to recommend that parents promote nature play for their patients—that is, suggesting to parents that they should have their children go outside and encourage play in an engaging and active way. Such active engagement with the natural environment is likely to benefit children of all ages, not to mention their parents.
Overall health benefits of nature play
Play is critical to healthy child development. That children will spontaneously play and become engrossed in imaginary worlds is not news to any parent or pediatrician, but given the recent emphasis on preschool structured activities, it seems that policymakers have ignored the importance of play. Both the No Child Left Behind Act of 20013 and the Race to the Top Initiative from 20094 emphasized formal academic instruction and standardized testing of even elementary school-aged children.
Fortunately, the AAP strongly emphasizes the importance of play for children and provides a useful definition of something that seems intuitive but difficult to describe: “Play often creates an imaginative private reality, contains elements of make-believe, and is nonliteral.”1 Play is engaging and social, helping children learn new skills as well as how to get along with others and manage their own desires and emotions. Play can take place in any location, and outdoor play is a particularly important context. For example, promoting recess is one way to improve academic achievement,5 and simply having preschoolers go outside to freely play increases levels of moderately vigorous physical activity.6
One fascinating study from Los Angeles compared 2 elementary schools that were matched for proximity, playground square footage, and playground design. Both locations had outdoor space for basketball, kickball, dodgeball, volleyball, 4-square, tetherball, and handball, as well as an open field and other nondesignated space near the school buildings. The control school did not change its playground environment but the intervention school replaced about 21,000 square feet of asphalt with green space. This green space included the introduction of trees, mulch, and boulders; the replacement of an asphalt field with grass and trees; and the replacement of another asphalt field with an “outdoor classroom.” This outdoor classroom was made of decomposed granite flooring, mulch, and log seating with plant borders.
In addition to the hoped-for decreases in sedentary activities for the children with the “greened” playground, there also was a significant decrease in physical and verbal conflicts among these children.7 There are a variety of reasons why increased exposure to natural areas may have helped decrease conflicts. Most notably, children shifted away from prescriptive games with rules (such as kickball or basketball) and more toward imaginative and unstructured play, which may have decreased the opportunity for conflicts and helped develop improved socialization.
Other studies have identified additional benefits of nature exposure that also could play a role. For example, adults who intentionally sought “nature exposure” for at least 10 minutes 3 times weekly for 8 weeks saw a significant decrease in salivary cortisol and alpha-amylase, important biomarkers for general stress.8 Other studies have observed a decrease in internalized mental health symptoms in adolescent girls who spend more than one-half hour per week outdoors9; a decrease in depression symptoms in adults who spend more time outdoors10; and even improved long-term outcomes in adults with severe depression who participated in a rehabilitation gardening program.11
1. Yogman M, Garner A, Hutchinson J, Hirsh-Pasek, Golinkoff RM; Committee on Psychosocial Aspects of Child and Family Health; Council on Communications and Media. The power of play: a pediatric role in enhancing development in young children. Pediatrics. 2018;142(3):e20182058.
2. Bravender T, Smith Bravender L. Expanding the definition of pediatric environmental health. Pediatr Res. May 11, 2019. Epub ahead of print.
3. Ladd HF. No child left behind: a deeply flawed federal policy. J Pol Anal Manage. 2017;36:461-469.
4. Dragoset L, Thomas J, Herrmann M, et al. Race to the Top: Implementation and Relationship to Student Outcomes (NCEE 2017-4001). Washington, DC: National Center for Education, Evaluation, and Regional Assistance, Institute of Education Sciences, U.S. Department of Education; 2016. Available at: https://files.eric.ed.gov/fulltext/ED569959.pdf. Accessed February 3, 2020.
5. Murray R, Ramstetter C; Council on School Health; American Academy of Pediatrics. The crucial role of recess in school. Pediatrics. 2013;131(1):183-188.
6. Razak LA, Yoong SL, Wiggers J, et al. Impact of scheduling multiple outdoor free-play periods in childcare on child moderate-to-vigorous physical activity: a cluster randomised trial. Int J Behav Nutr Phys Act. 2018;15(1):34.
7. Raney MA, Hendry CF, Yee SA. Physical activity and social behaviors of urban children in green playgrounds. Am J Prev Med. 2019;56(4):522-529.
8. Hunter MR, Gillespie BW, Chen SY. Urban nature experiences reduce stress in the context of daily life based on salivary biomarkers. Front Psychol. 2019;10:722.
9. Piccininni C, Michaelson V, Janssen I, Pickett W. Outdoor play and nature connectedness as potential correlates of internalized mental health symptoms among Canadian adolescents. Prev Med. 2018;112:168-175.
10. Beyer KM, Szabo A, Nattinger AB. Time spent outdoors, depressive symptoms, and variation by race and ethnicity. Am J Prev Med. 2016;51(3):281-290.
11. Währborg P, Petersson IF, Grahn P. Nature-assisted rehabilitation for reactions to severe stress and/or depression in a rehabilitation garden: long-term follow-up including comparisons with a matched population-based reference cohort. J Rehabil Med. 2014;46(3):271-276.
12. Reber SO, Siebler PH, Donner NC, et al. Immunization with a heat-killed preparation of the environmental bacterium Mycobacterium vaccae promotes stress resilience in mice. Proc Natl Acad Sci USA. 2016;113(22):E3130-E3139.
13. US Department of Health and Human Services. Physical Activity Guidelines for Americans. 2nd ed. Washington, DC: US Department of Health and Human Services; 2018.
14. Hagan JF, Shaw JS, Duncan PM, eds. Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents. 4th ed. Elk Grover Village, IL: American Academy of Pediatrics; 2017.
15. Brown DK, Barton JL, Gladwell VF. Viewing nature scenes positively affects recovery of autonomic function following acute-mental stress. Environ Sci Technol. 2013;47(11):5562-5569.