Slow breathing techniques before bedtime and the effects on sleep: A systematic review

Sleep insufficiency is prevalent and a widespread concern, having numerous negative effects on health and well-being and carries substantial financial costs. This systematic review aims to synthesize the evidence for the effectiveness of slow breathing to improve sleep. In adherence to PRISMA guidelines, searches were performed in Web of Science, MEDLINE, and PsycINFO in January 2025. Nine studies met the inclusion criteria (≤10 breaths/min, practiced before bedtime), encompassing 457 participants. Data on participant characteristics, sleep measures, heart rate variability measures, breathing protocol and days of intervention were extracted. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Our findings indicate that self-reported (n = 7) sleep duration and sleep quality improve after slow breathing before bedtime. Findings from studies measuring objective sleep; actigraphy (n = 2) and polysomnography (n = 3) are inconclusive. Three studies measuring sleep objectively used 1-day intervention protocol, whilst five self-reported sleep studies used intervention lasting 28-30 days. Six studies also examined heart rate variability, showing that slow breathing influences both the parasympathetic and sympathetic activity. More high-quality studies with longer days of intervention should be conducted to test the efficacy of slow breathing to improve sleep duration and sleep quality.