Adults with serious mental illness or serious mental illness (SMI) suffer from drastically higher rates of premature mortality (as much as a 10-25 years reduction in life expectancy) compared to the general population. Co-morbid medical conditions (i.e., heart disease, diabetes) are a fundamental cause. The iatrogenic cardiometabolic effects associated with antipsychotic drugs complicate matters. Underlying modifiable cardiometabolic risk factors (e.g., obesity, hypertension, poor physical fitness) are more prevalent and manifest earlier in the lifecourse in persons with SMI compared with the rest of society. Physical activity (PA) is an extensively recognized modifiable behavior that can reduce numerous cardiometabolic risk factors as well as improve quality of life (QOL) in people with SMI. Evidence-based methods for developing PA interventions among adults with SMI often incorporate individual attention, peer counselors, structured group PA, novel technology, self-monitoring, and behavior change strategies. However, challenges exist for both delivery and sustainability of effective PA treatment strategies for people with SMI in community settings. Indeed, development and testing of innovative, evidence-based PA interventions with SMI populations has been identified as a top research priority.

Parks are acknowledged as key community PA intervention settings given their low cost, ubiquity, and provision of structured and unstructured PA opportunities. Parks offer numerous physical, psychological, and social benefits associated with improved health behaviors and outcomes. Growing evidence, including our own, has documented relationships between access and use of parks and green space with greater PA, mood, and QOL, and less obesity, stress, morbidity and mortality. Further, outdoor PA is associated with increased enjoyment, satisfaction, and long-term adherence to PA, supporting it as an ideal approach to PA behavior change, especially among those with SMI. Despite potential benefits of park-based PA, few interventions have been tested rigorously, and none have focused specifically on adults with SMI. Certified peer specialists (CPSs), trained persons with lived recovery experience working in mental health settings, offer a potential delivery mechanism for park-based PA. Pulling from the Recovery Model incorporating elements of peer support and collaborative treatment approaches our long-term goal is to maximize the reach and clinical impact of evidence-based PA interventions to reduce cardiometabolic risk among adults with SMI through the use of existing CPS services and park-based PA.

The PARCS Study uses a novel approach for physical activity (PA) intervention delivery and sustainability among adults (18+yrs) with SMI through incorporation of freely available park resources into established peer counseling programs. The purpose of the PARCS study is two-fold: 1) Test the feasibility and acceptability of a CPS-led PA intervention among adults with SMI in park settings, and 2) evaluate the effectiveness of the PARCS intervention on a) SCT mechanisms of action (i.e., PA self-efficacy, goal setting, and social support) and b) PA, fitness, and health outcomes.

The PARCS Study aims to establish a sustainable, scalable, and reimbursable intervention model by leveraging existing resources (CPS services, parks) to reduce cardiometabolic risk in adults with SMI. Combining information from previous feasibility and effectiveness PA trials with adults with SMI, park-based PA literature, qualitative and quantitative feedback from pilot studies, the PARCS Study will optimize a 12-week PA intervention originally developed for people with chronic schizophrenia in an indoor setting, to an outdoor group exercise setting in parks. This study will utilize a two-arm randomized active control group design with pre- and posttest measures (n=100). Arm one, will consist of a 12-week park-based PA intervention, including sessions three days per week at times and days convenient for each participating facility. Under the guidance of trained research staff, four CPSs, who have experience working with peer groups, will be selected to help deliver the intervention. Park-based activity sessions will last approximately 60 minutes and consist of 10 minutes of warm up, 15 minutes of simple strength training activities, 25 minutes of moderate to vigorous aerobic activities (e.g., walking), and 10 minutes of cool down. The eight full-body strength training exercises will use body weight and/or elastic bands and will include a circuit of chest press, seated row, squat, shoulder press, biceps curl, triceps extension, calf raise, and reverse crunch. These activities have been selected to improve functional capacity of common daily living activities (e.g., ability to stand from seated position, lift groceries, use stairs, etc). During pilot studies, an ACSM-certified group fitness instructor developed scaled group-based activity sessions that progress in activity level over time with participants' capabilities. Sessions will strive to incorporate fun, social, adaptable activities that enable a wide variety of subjects to participate. Arm two, the active control group, will receive information about the importance of park-based PA, and a map of park locations but will not participate in park-based PA sessions. Participants in the control group will be invited to participate in park PA sessions after they have completed posttest. Participants in both groups will receive a Fitbit and usual care outpatient peer group treatment services, including routine counseling and health and wellness information/activities given by CPSs.