Objective This paper intends to provide inspiration and references for promoting public health in the protected area system by analyzing and comparing international experiences of the Healthy Parks Healthy People strategy globally. The exposure to natural environment and green spaces can increase the frequency of physical activities among urban and rural residents, which consequently enhances the immunity of body, reduces the potential risks of disease, and significantly improves the health level of the whole population in the full life cycle. Globally, protected areas have become a frontier that can provide opportunities to improve public contact with nature, as those large-size green spaces can extensively attract visitors and are likely to promote more enduring and intensive outdoor physical activities. Although such national programs as Protected Areas System Building in China and Healthy China Initiative have co-created an unprecedented historic opportunity to promote public health in the protected areas in China, it is still rare to see relevant researches and practice in China. The global movement of Healthy Parks Healthy People (HPHP) is widely identified as an effective approach to promoting public health in conservation areas. However, the experience of the movement has not been systematically studied or even noticed by Chinese scholars. In view of the aforementioned gaps, this research aims to achieve the following objectives: 1) summarize the global origin and development of HPHP movement; 2) identify representative countries that are successful in promoting HPHP, and draw lessons at national, regional and protected area scales; 3) summarize the global experience of HPHP movement to promote public health in protected areas and expound on potential countermeasures adaptable to China's protected area system.

Methods By literature review and content analysis, this research collects materials about HPHP from relevant literature, official websites, government reports and other documents, to analyze the historical trends of HPHP and select some representative countries. The research adopts a comparative method to compare similarities and differences between those selected countries or regions (Australia, U.S. and Europe), mostly from the following five aspects: vision, objective, partnership, key area and organization. In addition, the research conducts a case study on the Hot Spring National Park in the U.S.

Results The research finds that: 1) the strategy of HPHP was firstly put forward in 1999 by Parks Victoria in Australia, and by now this global movement has gone through three significant historical stages, namely the Formation Stage (1865–1999), Inception Stage (1999–2010) and Development Stage (2011 to present). 2) By comparing the HPHP system among Australia, U.S. and Europe, the research recognizes several distinctive features, including clear objective and vision, professional management agency, extensive partnership, legislation, regulation and strategic planning. 3) As the U.S. is acknowledged as the country with the most comprehensive HPHP system worldwide, the research analyzes and presents the HPHP implementation experience of the U.S. respectively from national, regional and local perspectives. Nationally, the Health and Wellness Executive Steering Committee (HWESC) was established in 2010 by the NPS to facilitate the program of "HPHP US". Regionally, a project entitled "HPHP: the Bay Area" was implemented to connect national parks, urban parks and other open green spaces to boost physical activities partnerships urban dwellers. From the perspective of protected area, Hot Spring National Park was showcased as a typical case, since it is the place where the notion of park prescription was preliminarily proposed, and is famous for all-around and distinctive HPHP promotion strategies. 4) The research classifies the U.S. experience in implementing HPHP projects into the seven aspects of clear vision orientation, scientific research, policy formulation, planning and design, multi-party cooperation, facility construction and event planning, all of which can provide imperative inspirations to China's protected area system.

Conclusion The research concludes that there are seven major strategies for promoting public health in China's protected areas system in response to several national programs such as Protected Areas System Building in China, Healthy China Initiative and National Park System Building in China. Specifically, the aforesaid strategies include clarifying objective and orientation, reinforcing scientific strategy, arranging management staff to secure the operation system, formulating multi-level plans to facilitate the implementation of relevant policies, developing widespread partnerships with governments, institutions, medical organizations, non-government organizations, media, etc., improving health facilities in protected areas, and designing diversified and attempting activities to attract visitors. Promoting public health based on the protected area system remains a frontier field in China, and there are plenty of knowledge gaps to be filled. This research presents as a comprehensive review of the global HPHP movement, based on which the inspirations put forward are still preliminary and conceptual in this almost blank research field. We hereby call for more theoretical and empirical researches on the healthy dimension of protected areas, which is an integral part of the social impact of protected areas.