79 and 1.21 for 30–149 min/week, 150–224 min/week and ≥ 225 min/week respectively versus < 30 min/week, p = 0.01 for trend). These findings differed very little in sensitivity analysis that omitted a small number of potentially influential cases (cases with standardised residuals < − 2 or > 2 for physical wellbeing (n = 46) and mental wellbeing (n = 60) models). Our findings suggest that greater time spent actively commuting is associated with higher levels of physical wellbeing, independent of time

spent in other domains of physical activity. In keeping with other studies of active commuting (Brown et al., 2004 and Dunn et al., 2005), we found that the largest benefit RNA Synthesis inhibitor was associated with participating in at least 45 min of active commuting per day. Although the adjusted regression coefficients of 0.48 and 1.21 points fall below VEGFR inhibitor the 3-point threshold for individual, ‘clinical’ significance in SF-8 summary measures (Bolge et al., 2009 and Samsa et al., 1999), such differences may still have important population-level

significance in settings such as Cambridge with a high prevalence of active commuting. However, contrary to studies of physical activity in general and to our own analysis of recreational physical activity, we found no evidence of a relationship between commuting and mental wellbeing (Hamer et al., 2009). This study benefitted from the use of detailed physical activity data to explore the contribution of specific domains of physical activity (e.g. active commuting) to overall health and wellbeing, as encouraged by others (Morabia et al., 2012). However the

cross-sectional design of this study is a key limitation: it is impossible to draw conclusions regarding the specific causal relationship between AC and physical wellbeing. It is also unclear how AC and weight status interact along the causal pathway, and what direction of causality (if any) underlies the strong association. Finally, further studies are required to assess the generalisability of these findings. In particular, we have previously argued that almost all participants in this relatively affluent sample could potentially afford to travel by car or bus (Goodman et al., 2012). They could therefore determine many their commuting practices in light of other non-financial considerations, including those of protecting their bodies from injury, over-exertion or the adverse effects of a sedentary lifestyle. It is possible that associations between AC and physical wellbeing would be less favourable in poorer settings where active travel may be imposed rather than chosen, and may be experienced as tiring or stressful (Bostock, 2001). In conclusion, the findings presented here suggest that greater participation in active travel may contribute to improved health by increasing physical wellbeing.