Effects of Forest Walking: A Systematic Review and Meta-Analysis

Background and objective: Forest walking has attracted growing attention as an intervention for enhancing physical activity and alleviating stress. However, existing studies remain fragmented, making it difficult to synthesize current research findings. Therefore, this study aims to analyze current state of research through a systematic review, assess study quality via risk-of-bias evaluation, and quantify the effects of forest walking through meta-analysis.Methods: Based on the PICO criteria, a total of 42 articles were identified and included in the analysis. First, publication trends by year, research disciplines, participant characteristics, walking characteristics, forest trail information, outcome measures, and study designs were examined to assess the status of the field. Second, risk-of-bias assessments were conducted to evaluate the quality of evidence. Third, a meta-analysis was performed on outcome measures reported in five or more studies, including nine physical and physiological outcomes and seven psychological outcomes. Finally, moderator analyses were conducted to identify variables influencing the intervention outcomes.Results: The analysis of research trends showed that studies on forest walking have been continuously reported since 2008 and have involved diverse populations. Interventions were predominantly delivered as multi-session programs, most commonly comprising 30- to 60-minute walking sessions conducted over 8–12 weeks with a total of 21 or more sessions. Approximately two-thirds of the studies prescribed a target exercise intensity. Outcome measures encompassed various physical, physiological, and psychological outcome measures, and study designs included randomized controlled trials, non-randomized controlled trials, and other designs. However, descriptions of forest trail characteristics were often insufficient. The risk-of-bias assessment revealed a high overall risk of bias, indicating limitations in the quality of evidence. The meta-analysis demonstrated that forest walking had positive effects on physical, physiological and psychological outcomes, although these effects varied depending on sex, health status, walking session duration and frequency, and study design.Conclusion: Forest walking has consistently been shown to produce beneficial effects on both physical and mental health, suggesting that it may serve as an effective intervention for contemporary populations suffering from chronic physical and mental health problems.