Long-term dynamics in physical activity behaviour across the transition to parenthood

Objectives: Gaining a deeper understanding of the dynamic relationships between the transition to parenthood and moderate-to-vigorous physical activity (MVPA) amongst men and women in Australia. Methods: 12 years of nationally representative panel data from the Household, Income and Labour Dynamics in Australia Survey and a piecewise pre/post fixed-effect modelling strategy that controls for person-specific unobserved effects and allows for non-linear associations are used. Results: Both men and women decrease the frequency of MVPA in the years preceding the birth of their first child. An abrupt fall amongst men and a smooth, non-linear decreasing trend amongst women are apparent in the post-birth years. Neither men nor women recover their pre-birth MVPA frequency in subsequent years. Conclusions: Parenthood is an important factor influencing MVPA, with more marked impacts on women’s than men’s behaviour. Policymakers interested in promoting MVPA should focus on parenthood as a critical deterring factor that can trigger long-term trends of low MVPA. The proposed model can be expanded to explore the influence on MVPA of other life-course transitions.