Objective: The aim of this study was to examine changes and the bi-directional relationship in sleep and movement, and health and well-being among new parents and differences by sex.
Methods: This secondary data analysis included both conditions from a randomized control trial to improve new parents'physical activity [PA] and recruited couples. Parents (n = 181, 117 couples represented 31.5 ± 4.4 years, 51.3% women, 83.3% White) completed questionnaires on regular overnight sleep duration, PA, mental health (perceived stress), physical health (physical quality of life [PQoL]), and well-being (life satisfaction) at 2-, 4-, 6-, and 8-month postpartum. Random-intercept cross-lagged panel models were stratified by sex to examine changes in sleep and PA with health and well-being across time.
Results: Sleep and stress were interrelated at different times for fathers (2 months), and mothers (8 months). Sleep and PQoL improved across time, with mothers reporting less sleep than fathers at 4 and 6 months. PQoL at 4 months was related to MVPA at 6-months. Life satisfaction and PA at 2 months was related to PA at 4 months.
Conclusion: Mothers and fathers experienced different sleep and stress trajectories. Mental health improved postpartum with early connections to PA. Supporting the 24-hour movement behavior cycle and mental health across the parenthood transition may benefit couples.