Optimal dose of aerobic exercise for improving postpartum depression, anxiety, and quality of life: a meta-analysis of randomized controlled trials and dose–response analysis

Background: Postpartum depression, anxiety, and reduced health related quality of life (HRQoL) are common in the first year after childbirth, a period characterized by marked hormonal fluctuations, sleep disruption, and psychosocial role transitions that increase vulnerability to emotional distress, and have substantial consequences for maternal and child well-being. Aerobic exercise is increasingly recommended as a low-risk behavioral strategy, as it has been shown to improve mood, reduce stress, and modulate neurobiological pathways associated with depression, yet its effectiveness and optimal prescription parameters for postpartum mental health remain unclear. This study evaluated the effects of aerobic exercise on depressive symptoms, anxiety, and HRQoL, and characterized corresponding dose response patterns. Methods: PubMed, Embase, CENTRAL, Web of Science, and Google Scholar were searched from inception to 31 October 2025. Randomized controlled trials lasting at least four weeks and comparing structured aerobic exercise with inactive or minimal control conditions were included. Outcomes were depressive symptoms, anxiety, and HRQoL assessed using validated instruments. Random effects meta-analyses generated standardized mean differences (SMDs). Dose response relationships were examined using model-based methods. Results: Seventeen trials involving 2,865 women met inclusion criteria. Aerobic exercise significantly reduced depressive symptoms (SMD - 0.37, 95% CI - 0.60 to -0.14), with larger improvements in women with baseline depression and in interventions delivered postpartum. Dose response analysis showed a U-shaped pattern, with maximal benefit at approximately 570 MET minutes per week. No significant effect was found for anxiety (SMD - 0.11, 95% CI - 0.31 to 0.09). Aerobic exercise improved HRQoL (SMD 0.45, 95% CI 0.29 to 0.60), and an inverted U-shaped dose response indicated optimal gains near 420 MET minutes per week. Conclusion: Aerobic exercise reduces postpartum depressive symptoms and improves HRQoL. Optimal effects were observed at approximately 570 MET minutes per week for depression and 420 MET minutes per week for HRQoL, suggesting that a weekly volume of 400 to 600 MET minutes may be a practical target in postpartum care. Evidence remains insufficient to confirm anxiolytic effects.