**Background:** Regular physical activity is essential for health, yet only 1 in 4 U.S. adults meet combined aerobic and muscle-strengthening guidelines. The built environment—where people live, learn, work, and play—can either support or inhibit physical activity. The Community Preventive Services Task Force recommends built environment strategies combining activity-friendly routes (pedestrian, bicycle, transit) with land use components connecting everyday destinations. CDC's Active People, Healthy Nation initiative aims to help 27 million Americans become more physically active by 2027. However, implementation of physical activity–supportive policies remains low; the National Complete Streets Coalition reports only 1,600 jurisdictions have adopted Complete Streets policies, a fraction of all U.S. jurisdictions, with variable policy quality. Since 2004, CDC has supported physical activity policy research networks through the Prevention Research Centers program, including PAPRN (2004–2019) and PAPRN+ (which emphasized translation of evidence-based policy into practice).
**Methods:** PAPREN was established in 2019 as the next generation network, co-led by researchers at the University of Massachusetts Medical School and the University of Illinois Chicago School of Public Health (the Coordinating Center), funded by CDC's Division of Nutrition, Physical Activity, and Obesity. The network prioritizes CPSTF recommendations for built environment approaches creating activity-friendly routes to everyday destinations, with health equity as a guiding principle. PAPREN has a multilayered leadership structure: an executive committee (Coordinating Center team plus CDC DNPAO liaison), a 16-member steering committee (executive committee plus work group co-chairs), and a five-member external advisory committee of experts in transportation, land use, and public health. Membership is open and has two tiers: general members (receive communications, participate in events) and affiliate members (active in work groups, participate in projects). As of May 15, 2021, PAPREN had over 550 members. The network supports activities in three areas: (a) growing professional capacity and collaboration; (b) building new research evidence; and (c) supporting translation of research to practice.
**Key Results:** PAPREN supports five domain-specific work groups (transportation policy and planning, rural active living, parks and greenspace, school wellness, and worksite wellness) and one cross-cutting work group on equity and resilience. Each work group is led by co-chairs and supported by a fellow (graduate student, postdoctoral fellow, or junior faculty). Work group projects focus on built environment issues for use by decision-makers and practitioners, including CDC's State Physical Activity and Nutrition program, High Obesity Programs, and Racial and Ethnic Approaches to Community Health program recipients. Examples include the transportation policy and planning work group exploring strategies communities use to maintain and fund sidewalks, and the equity and resilience work group characterizing anti-displacement strategies proposed or implemented in the United States. Network activities include bimonthly grand rounds webinars featuring high-profile speakers (e.g., addressing systemic racism's impact on physical activity opportunities, and place-based changes to reduce gun violence), alternating with videoconference network meetings featuring CDC and Active People, Healthy Nation partners. Communications include the PAPREN website (www.papren.org), a monthly newsletter (The PAPREN Post), a blog, and Twitter (@PAPREN1).
**Clinical Implications:** PAPREN is positioned as a key research partner of CDC's Active People, Healthy Nation initiative, uniquely situated at the intersection of research and practice. By intentionally extending membership beyond traditional public health disciplines to include planning, transportation, and engineering, the network addresses the cross-sector collaboration required for built environment changes. PAPREN-affiliated research aims to fill two main research-to-practice gaps: (a) evaluation research demonstrating long-term policy impacts on physical activity and health outcomes; and (b) implementation research identifying evidence-based strategies to improve practitioner capabilities in policy processes. The network's emphasis on health equity as a guiding principle across all activities, combined with its focus on generating evidence and tools for states and communities, supports the broader goal of ensuring equitable access to physical activity opportunities.