Physical activity (PA) can help prevent and control many chronic diseases, yet levels of PA remain low among U.S. adults (Powell et al., 2011, Troiano et al., 2008). National plans, such as Healthy People 2020 and the National Physical Activity Plan, call for specific actions to increase PA among all age groups, including improving environmental supports for PA(Pate, 2009, U.S. Department of Health and Human Services, 2012). Outdoor recreation areas (ORAs; e.g., parks, trails, green spaces) are associated with greater PA in community-dwelling adults and provide a low-cost resource for PA (Kaczynski and Henderson, 2008, Sallis et al., 2012). Past cross-sectional research on parks has found that ORA-related factors such as proximity, park features, quality, and safety, are associated with ORA use (Carlson et al., 2010, Kaczynski and Henderson, 2008, Kaczynski et al., 2008, Schoffman et al., 2014). However, little is known about longitudinal patterns of ORA use and what factors predict changes in use of these spaces specifically for PA. Therefore, the present analysis examines individual and neighborhood-level predictors that explain changes over a 6-month period in ORA use for PA.

Descriptive characteristics of the sample are shown in Table 1. On average, participants were 49.4+13.3 years of age, with some college education (78.3%), two-thirds (66.1%) were Black, and the majority were women (85.7%). There was a mean increase in group ORA use of 2.1+0.4 days/month from baseline to 6 months. As shown in Table 2, cross-sectionally, higher levels of the following predictors were associated with greater group average ORA use: percentage of time in MVPA, self-efficacy, social support from family, friends, and walking group. Longitudinally, increased social support from friends and rating of lighter motorized traffic (marginally significant) were associated with increased group ORA use. Additionally, longitudinal increases in the percentage of time spent in MVPA and more favorable rating of the neighborhood as a place to walk were both associated with decreased group ORA use.

We tested a range of individual and environmental characteristics to examine associations with use of ORAs for PA both cross-sectionally and longitudinally. The findings of this analysis expand our understanding of factors related to active ORA use in several ways. For example, self-efficacy and social support from family, friends, and walking group were cross-sectionally associated with higher average group ORA use, although only social support from friends was longitudinally associated with increased ORA use. The cross-sectional findings about self-efficacy are consistent with past research on overall PA participation (Bauman et al., 2012), but also add to a growing literature on relationships between psychosocial attributes and use of environmental resources for PA (Carlson et al., 2012). Some research shows that positive neighborhood environments especially benefit those with lower self-efficacy and other similar at-risk populations (Kaczynski et al., 2012; Lee et al., 2007) and that parks provide appealing venues for PA (Hansmann et al., 2007), but more research is needed to better understand how opportunities for use of ORAs may mitigate individuals’ self-efficacy constraints (Voorhees et al., 2011).

The strong findings relating social support and active ORA use may be reflective of the group-based nature of the present intervention, but are also in line with previous research showing greater park usage and PA within areas possessing higher levels of social capital (Broyles et al., 2011). Further, the cross-sectional findings linking social support and ORA use in the current study align with previous data indicating that women reported higher perceived support for PA intentions, and feelings of safety and enjoyment when they visited ORAs with others (Krenichyn, 2004). This indicates that a bidirectional relationship between ORA use and perceived support for PA may exist, such that ORA use may increase perceived support for PA. Future interventions should build on and leverage the potential for social participation and support for PA within ORA settings. Additionally, walking groups were comprised of diverse groups of people, some including friends, neighbors, coworkers, and potentially more distant acquaintances. A potential area for further investigation might be to more closely measure the composition of the walking group, and then compare the levels of perceived social support experienced by participants.

Cross-sectional MVPA was associated with ORA use, similar to the findings of other studies that have shown that higher levels of ORA use are correlated with higher levels of PA (Kaczynski and Henderson, 2008, Sallis et al., 2012). However, it is surprising that longitudinal increases in time spent in MVPA were associated with a decrease in group ORA use. Perhaps participants and groups who increased their MVPA during the study were engaging in more vigorous activities than could be accomplished within the available ORAs and with walking groups. Indeed, much park use is observed as sedentary (Kaczynski et al., 2011) and interventions are needed within parks to encourage shifting some inactive behavior to PA (Kaczynski et al., 2014b). In addition, the intervention strategies that comprised this study encouraged participants to participate in PA in a variety of contexts, including but not limited to, ORAs (Wilcox et al., 2014). It is possible that the walking groups collectively decided that other locations (e.g., neighborhood streets, school facilities) were more suitable for their walking sessions in terms of distance, accessibility, or safety compared to the ORAs. Future research could include the wear of geographic positioning system (GPS) devices in addition to the accelerometers to better assess the specific location and contexts of participants’ PA (Evenson et al., 2013).Similarly, negative perceptions of safety in ORAs like parks have been frequently cited as a barrier for visitation and physical activity behaviors in such settings (Bai et al., 2013). The group-based component of the intervention inherently includes a strong social component to facilitating PA. It is possible that any negative perceptions about park and recreation locations could have been shared in the group setting and negatively influenced PA in ORA settings over time. Assessing perceptions of safety and other factor affecting ORA use in the future may provide better insight in explaining this longitudinal relationship.

Previous cross-sectional research has found that perceptions of the neighborhood environment, including its safety and accessibility for engaging in PA, is associated with park and trail use (Paxton et al., 2005). However, examination of these factors produced mixed results in our study. For example, we found no association (cross-sectional or longitudinal) between availability of sidewalks and ORA use or rating of quality of street lighting and ORA use. At the same time, ratings of lighter motorized traffic were marginally related to increased ORA use, which is consistent with past research about neighborhood traffic speed and park visitation among adults (Kaczynski et al., 2014a). However, rating one’s neighborhood as a pleasant place to walk was related to decreased ORA use over time, which may simply represent a displacement of PA from parks and trails to other neighborhood settings (e.g., sidewalks, streets).

This study relied primarily on self-reported measures of ORA use and influencing factors, but examined a range of personal and neighborhood-level predictors of both cross-sectional and longitudinal ORA use within a racially-diverse sample. Better understanding how social and physical environmental characteristics impact ORA use for PA can lead to more effective intervention strategies and warrants greater individual and collective attention in future research and public health promotion efforts.