Purpose:   To investigate the relationship between the spatial features of exercise failities and physical activity in adolescents.

  Methods:   Participants were 329 students recruited from six junior schools in Beijing.The ActiGraph GT3X+ accelerometers were applied to measure the light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous intensity PA (MVPA) in various time segments, i.e., average across a week, weekdays, weekday non-school hours, and weekend days.The spatial features of exercise failities within the neighborhood (1 km, 2 km, 3 km, and 5 km buffer) were analyzed by ArcGIS V10.0 software.

  Results:   Participants do an average of 39.96±17.19 min/day MVPA and 12.5% of which meet recommended 60 min/day MVPA.Participants are more active on weekdays than on weekend days, and boys are more active than girls.Number of exercise failities within 3 km buffer is positively associated with MPA and MVPA in weekday non-school hours.Number of exercise failities and area proportion of parks within 1 km, 2 km, 3 km, and 5 km buffers are positively associated with MPA on weekend days.Number of exercise failities within the 2 km buffer is positively related to VPA on weekend days.Number of exercise failities within 2 km, 3 km, and 5 km buffers is positively related to MVPA on weekend days.

  Conclusion:   PA levels of adolescents in Beijing are extremely low.Adolescents are more active on weekdays and boys are more active than girls.Increasing number of exercise failities and park area in the neighborhood may help to promote PA levels during weekday non-school hours and weekend days in adolescents.