Intradialytic Exercise Interventions to Enhance Physical Activity Levels in Hemodialysis Patients: A Systematic Review and Meta-analysis.

Introduction: Physical activity levels in hemodialysis patients are low and continue to decline, increasing mortality risk. Intradialytic exercise improves hemodialysis patients' quality of life and enhances their physical and psychological health. But, existing reviews fail to provide the best evidence for enhancing physical activity levels in this population. This study is to examine the efficacy and safety of intradialytic exercise for hemodialysis patients.

Methods: MEDLINE, EMBASE, the Cochrane Library CINAHL, Web of Science, PubMed, Wan Fang data, and SinoMed were searched up to March 2025. The reference lists of eligible studies were systematically checked to ensure comprehensive coverage of the relevant literature. Two independent reviewers searched the databases, selected trials, conducted a bias assessment, and extracted the data. Meta-analysis was conducted using Review Manager Version 5.4.1.

Results: Of the 3880 studies that were screened, 23 studies involving 1114 patients were identified. Three types of exercise, seven exercise durations, and four exercise intensity standards were compared, and physical activity level, VO2 peak, muscle strength, and muscle mass were reported. Statistically, in terms of exercise type, combined aerobic and resistance exercise improved physical activity levels (SMD=0.99, 95% CI: 0.44 to 1.55) and VO2 peak (SMD=1.01, 95% CI: 0.56 to 1.46). Meanwhile, resistance exercise significantly improved muscle strength (SMD=0.52, 95% CI: 0.24 to 0.81). In terms of exercise intensity, moderate exercise intensity significantly improved Physical activity levels (SMD=0.55, 95% CI: 0.22 to 0.88), VO2 peak (SMD=0.59, 95% CI: 0.12 to 1.07), and muscle strength (SMD=0.37, 95% CI: 0.11 to 0.63). Additionally, higher-intensity exercise also significantly improved muscle strength (SMD=1.02, 95% CI: 0.51 to 1.53). As for exercise duration, programs lasting up to 3 months positively impacted Physical activity levels (SMD = 0.65, 95% CI: 0.17 to 1.13) and VO2 peak (SMD = 0.70, 95% CI: 0.19 to 1.21). Furthermore, exercise extending up to 6 months significantly improved muscle strength in hemodialysis patients (SMD = 0.41, 95% CI: 0.18 to 0.64).

Conclusion: Evidence shows that intradialytic exercise intervention improves physical activity levels, VO2 peak, and muscle strength in hemodialysis patients. Future clinical intervention studies could conduct direct comparisons of protocols with different exercise modalities, intensities, and durations.