Associations between availability of facilities within three different neighbourhood buffer sizes and objectively assessed physical activity in adolescents.

This study aims to explore whether objectively measured availability of parks and sports facilities within three different buffer sizes are associated with moderate-to-vigorous physical activity (MVPA) among adolescents, and to identify potential cognitive mediators of this association. Data were obtained from adolescents (N=209, mean age: 14.5 (SD: 0.6) years) at the follow-up measurement of the Children Living in Active Neighbourhoods study in 2004. MVPA was measured using accelerometers. Availability of parks and sport facilities were measured within 400, 800 and 2000 m buffers around participants' residential homes. Potential mediators (self-efficacy, attitude and the perceived availability of parks and sports grounds) were measured by self-administered questionnaires. No direct association was found between the objectively measured availability of facilities and objective assessments of MVPA and no evidence for mediation by cognitions was found in any of the buffer sizes. More specific and sensitive measures may be needed to understand environmental correlates of MVPA.