Effects of Aquatic Exercise on Sleep Quality in Patients with Chronic Diseases: A Meta-Analysis

Background/Objectives: This study systematically synthesized the evidence on the effectiveness of aquatic exercise (AE)-based interventions for improving sleep quality in patients with chronic diseases and identified key moderating factors. Methods: A meta-analysis of 11 randomized controlled trials sourced from Google Scholar, PubMed, Web of Science, Embase, Cochrane Library, and Scopus (published between 2016 and 2025) was conducted. Sleep quality was assessed using subjective tools (e.g., PSQI). Results: While AE-based interventions showed potential for enhancing nighttime sleep quality (standard mean difference = 0.825, p < 0.001), high statistical heterogeneity (I² = 93.41%) was observed. Given this variance, the analysis prioritized the clinical outcomes of specific patient populations over the pooled effect size. Preliminary evidence suggests significant improvements were confirmed in populations with post-COVID syndrome (p < 0.001), Parkinson's disease (p = 0.002), and chronic back pain (p = 0.008). Conversely, no significant benefits were observed in fibromyalgia (p = 0.191), ankylosing spondylitis (p = 0.737), or type 2 diabetes (p = 0.836). Moderator analysis further indicated that the mode of AE might influence outcomes, with recreational aquatic therapy and deep-water running suggesting superior efficacy compared to resistance training. Conclusions: AE-based interventions were suggested as an effective intervention for improving sleep quality. The observed benefits likely stem from the synergistic effects of physical exercise and the unique physiological properties of the aquatic environment, such as buoyancy and hydrostatic pressure. However, the field relies heavily on subjective questionnaires and lacks physiological mechanism studies. These findings provide a preliminary evidence-based framework for clinicians to develop targeted AE-based interventions for chronic disease patients.