Coastal proximity and physical activity: Is the coast an under-appreciated public health resource?

Highlights

• People in England who live near the coast report better health than those inland.

• We investigated whether this was related to greater levels of physical activity.

• Results found support on the west but not east coast of England.

• Further research is needed to understand these large regional differences.

Abstract

Background

Recent findings suggest that individuals living near the coast are healthier than those living inland. Here we investigated whether this may be related to higher levels of physical activity among coastal dwellers in England, arising in part as a result of more visits to outdoor coastal settings.

Method

Participants (n = 183,755) were drawn from Natural England's Monitor of Engagement with the Natural Environment Survey (2009–2012). Analyses were based on self-reported physical activity for leisure and transport.

Results

A small, but significant coastal proximity gradient was seen for the likelihood of achieving recommended guidelines of physical activity a week after adjusting for relevant area and individual level controls. This effect was statistically mediated by the likelihood of having visited the coast in the last seven days. Stratification by region, however, suggested that while the main effect was relatively strong for west coast regions, it was not significant for those in the east.

Conclusions

In general, our findings replicate and extend work from Australia and New Zealand. Further work is needed to explain the marked regional differences in the relationship between coastal proximity and physical activity in England to better understand the coast's potential role as a public health resource.

Introduction

Populations living near the coast in England are healthier than those inland (Wheeler et al., 2012) and longitudinal data suggest that individuals are healthier during periods when they live closer to the coast (White et al., 2013a). One factor may be that living closer to the coast fosters higher levels of physical activity (PA) and consequent health benefits. Regular PA is associated with a reduced risk of obesity, diabetes, heart disease and depression (NICE, 2008, NICE, 2012) and can be just as effective as medication in reducing associated mortality (Naci and Ioannidis, 2013). Studies in Australia and New Zealand, mostly using relatively small samples, report a positive association between living near the coast and rates of self-reported PA (mostly walking; Ball et al., 2007, Bauman et al., 1999, Humpel et al., 2004, Witten et al., 2008). However, as far as we are aware this issue has not previously been investigated outside of Australasia and in countries, such as England, with different cultures and climates.

A further issue is the lack of direct evidence that any coastal proximity effect really is due to greater time spent being active at the coast. Evidence exists that people who live near the sea do spend more leisure time at the coast (White et al., 2013a, Schipperijn et al., 2010) but we know of no research that has explored the relationship between frequency of coastal leisure visits and PA. Establishing this relationship is necessary if visit frequency is to account for any association between coastal proximity and PA, rather than activity being conducted in other locations such as gyms. A similar approach has been taken in studying whether associations between residential neighbourhood green space and PA are mediated by time spent in green space (e.g. Coombes et al., 2010, Lachowycz and Jones, 2014, Ord et al., 2013) but this is yet to be extended to coastal analysis.

Finally, there has been little exploration of potential moderators of any coastal proximity–PA relationship, in part because the relatively small sample sizes of the few studies that have been conducted prevent such an analysis. However, moderators such as socio-economic status (SES, Ord et al., 2013, Jones et al., 2009) and gender (Wheeler et al., 2010) have been identified in studies of the relationship between local green space and PA. While findings from these studies are mixed, there is some evidence of effect modification, which may also be important for coastal proximity and PA. In previous research we found a stronger association between residential coastal proximity and population self-reported health in more deprived areas (Wheeler et al., 2012) and this may also be reflected in PA in these areas. Moreover, the Australian studies investigating coastal proximity and PA revealed relatively strong effects for women (Ball et al., 2007, Humpel et al., 2004) but not men (Humpel et al., 2004). Other potential demographic moderators such as age have not been explored previously, nor have issues such as season of data collection or geographical location. Season and location, especially latitude, may play a role due to higher temperatures encouraging more interaction with the coast at some times of the year or in some places.

The current research addressed these underexplored issues using a large nationally representative English survey, the Monitor of Engagement with the Natural Environment (MENE, Natural England, 2011a). Specifically, we asked three key questions: 1) Is greater residential coastal proximity associated with increased PA in England?; 2) If there is an association, is it mediated by visits to the coast (i.e. due to time actually spent in this environment)?; and 3) Is there any evidence of moderation of the association by age, sex, SES, season or region?