Background In the largely cross-sectional literature, built environment characteristics such as walkability and recreation centres are variably related to physical activity. Subgroup-specific effects could help explain inconsistent findings, yet few studies have compared built environment associations by key characteristics such as sex or life stage.

Methods Using data from the National Longitudinal Study of Adolescent Health (wave I 1994–5, wave III 2001–2; n=12 701) and a linked geographic information system, cross-sectional relationships between moderate to vigorous physical activity (MVPA) bouts and built and socioeconomic environment measures were estimated. Negative binomial generalised estimating equation regression modelled MVPA as a function of log-transformed environment measures, controlling for individual sociodemographics and testing for interactions with sex and life stage (waves I and III, when respondents were adolescents and young adults, respectively).

Results Higher landscape diversity (coefficient 0.040; 95% CI 0.019 to 0.062) and lower crime (coefficient −0.047; 95% CI −0.071 to −0.022) were related to greater weekly MVPA regardless of sex or life stage. Higher street connectivity was marginally related to lower MVPA (coefficient −0.176; 95% CI −0.357 to 0.005) in females but not males. Pay facilities and public facilities per 10 000 population and median household income were unrelated to MVPA.

Conclusions Similar relationships between higher MVPA and higher landscape diversity and lower crime rate across sex and life stage suggest that application of these environment features may benefit broad populations. Sex-specific associations for street connectivity may partly account for the variation in findings across studies and have implications for targeting physical activity promotion strategies.