Does self-selection influence the relationship between park availability and physical activity?

Increased proximity to parkland is associated with physical activity (PA). This study explored the extent to which self-selection--the idea that active persons simply seek out neighborhoods more endowed with active resources--influences the relationship between park availability and PA.

In August 2007, measures of parkland availability within 1 km, importance placed on living near parks, and park-based PA participation were assessed for 585 adults in Waterloo, Ontario.

Logistic regression revealed that (i) participants who placed greater importance on neighborhood open space were not more likely to live near more parkland; (ii) both park importance and park space availability were associated with increased, and relatively equal, odds of engaging in at least some park-based PA; and (iii) participants who placed a low importance on living near parks but had a higher amount of park space nearby were significantly more likely to engage in park-based PA than participants who also placed a low importance on parks but had less nearby park space.

The issue of self-selection does not solely account for the relationship frequently observed between park space availability and PA. Future prospective and intervention studies are needed to draw more definitive conclusions about causality.