Conclusions
The results of this study highlight the need to disentangle the impact of engagement with different tailored content to improve the efficacy of web-based tailored interventions, especially for improving PA in African American families. Among parents, MVPA did increase with greater log-in duration for the PA and sedentary activity sessions, suggesting that greater exposure to the tailored PA-related content had a positive impact on parents’ PA. Future web-based studies may benefit from integrating program use data that captures engagement with different types of tailored theoretical construct components.This research was supported by a grant (R01 HD072153) funded by the National Institute of Child Health and Human Development to DKW and by a grant from the National Institute of General Medical Sciences (T32 GM081740).Conflicts of Interest: None declared.Fixed effects of log-in status and duration on moderate to vigorous physical activity for parents (N=119).Fixed effects of log-in status and duration on moderate to vigorous physical activity for adolescents (N=119).