The relationship between built environments and physical activity: a systematic review.

OBJECTIVES We conducted a systematic review of the literature examining the relationship between built environments (e.g., parks, trails, sidewalks) and physical activity (PA) or obesity rates. METHODS We performed a 2-step inclusion protocol to identify empirical articles examining any form of built environment and any form of PA (or obesity rate) as the outcome. We extracted data from included abstracts for analysis by using a standard code sheet developed for this study. RESULTS Of 169 included articles, 89.2% reported beneficial relationships-but virtually all articles utilized simple observational study designs not suited for determining causality. Studies utilizing objective PA measures (e.g., pedometer) were 18% less likely to identify a beneficial relationship. Articles focusing on children in community settings (-14.2%), those examining direct measures of obesity (-6.2%), or those with an academic first author (-3.4%) were less likely to find a beneficial relationship. CONCLUSIONS Policymakers at federal and local levels should encourage more rigorous scientific research to determine whether altered built environments will result in increased PA and decreased obesity rates.