Background: Programs promoting population health through physical activity (PA) and exposure to nature are popular, but few have been evaluated in randomized-controlled trials (RCTs). Objective: To investigate the effectiveness of a park prescription intervention (PPI) for improving total moderate-to-vigorous PA (MVPA), other PA related behaviors, quality of life (QoL) and cardio-metabolic health among adults. Methods: Healthy individuals aged 40 to 65 years were recruited through community health screenings and randomly assigned to 1) PPI: face-to-face Park Prescription + invitation to weekly exercise sessions in parks, or 2) control: standard PA materials. After the six-month intervention, participants completed accelerometer assessments, questionnaires on health behaviors and QoL, and health screenings. Independent sample t-tests were used to compare outcomes between groups, with secondary analysis adjusted for co-variates via multiple linear regression. A p-value <0.05 was considered statistically significant. Results: Eighty participants were allocated to each group. Participants with mean age of 51.1 (Standard Deviation: 6.3) years were predominantly female (79%) and of Chinese ethnicity (81%). Participation in the group exercise started at 48% and declined to 24% by week 26. At six-months, 145 (91%) participants attended health screenings for outcome measure collection, and 126 (79%) provided valid accelerometer data. Time spent in MVPA favored the PPI group but this difference was not statistically significant (4.4 (− 43.8, 52.7) minutes/week; when removing 2 extreme outliers 26.8 (− 9.7, 63.4) minutes/week). Time spent in parks (147.5 (2.1, 292.9) minutes/month), PA in parks (192.5 (59.5, 325.5) minutes/month), and recreational PA (48.7 (1.4, 96.0) minutes/week) were significantly greater in the PPI group. PPI also significantly improved psychological QoL (4.0 (0.0, 8.0). Discussion: PPI improved park use, PA in parks, recreational PA, and psychological QoL but not total MVPA. Future RCTs’ are warranted to investigate PPI in different target populations and to provide further evidence for improvements in health outcomes. Trial registration: ClinicalTrials.gov NCT02615392, 26 November 2015.

Background: Relationships between park access, park use, and wellbeing remain poorly understood. The objectives of this study were to investigate: (1) perceived and objective park access in relation to park use and physical activity in parks; and; (2) perceived and objective park access, park use and physical activity in parks and their associations with wellbeing. Methods: An interviewer-assisted survey collected data on perceived time to walk to parks, park use time, park physical activity time and wellbeing (using a scale containing nine domains) amongst adult participants of the Singapore Multi-Ethnic Cohort. Geospatial maps of parks and the “walkable” street networks were created for the city-state of Singapore to objectively determine distances to accessible points on park boundaries. Multiple linear regression models estimated the importance of park access to park use and associations of park access and park use with wellbeing, adjusting for potential confounders. Results: Participants’ (n = 3435) average age was 48.8 years (SD, 12.8), 44.8% were male and 72.6% were of Chinese ethnicity. Better perceived but not true park access was significantly associated with greater park use. Park access (perceived or true) was not associated with physical activity time in parks. Greater participant park time and physical activity time in parks were associated with higher wellbeing scores (p < 0.001). The differences in wellbeing scores between the reference groups, who spent negligible time in parks, and the highest quartiles of time in parks (10.8 h/month) and physical activity in parks (8.3 h/month) were 3.2 (95% CI 2.1–4.4) and 4.2 (95% CI 4.1–6.3) points out of 100 respectively. These associations were similar for most domains of wellbeing, with clear dose-response relationships. Conclusions: While perceived park access was strongly associated with park use and well-being, true park access was not, and neither park access measure was associated with park physical activity. Future studies could investigate the influence of park attributes on park use, physical activity in parks and wellbeing. The consistent associations of park use and particularly physical activity in parks with wellbeing suggest that promoting park use, and especially physical activity in parks, is a promising strategy for improving wellbeing in urban settings.