Background: Hemodialysis (HD) patients experience severe physical deconditioning due to extremely low physical activity, prolonged sedentary behavior, and progressive muscle wasting. These changes accelerate frailty, impair functional independence, reduce quality of life (QoL), and increase hospitalization and mortality risks. Sarcopenia is now recognized as a key predictor of poor outcomes in this population.

Objective: To synthesize evidence on physical activity, sedentary behavior, muscle wasting, and exercise interventions in HD patients, and to evaluate the physiological and functional benefits of interdialytic exercise.

Methods: A structured narrative review was conducted using PubMed, Scopus, Web of Science, and Google Scholar for studies published from 2002–2025. Eligible studies included observational studies, randomized controlled trials, clinical trials, and systematic reviews involving adult HD patients. Data were extracted and thematically synthesized.

Results: HD patients exhibit extremely low physical activity and spend approximately 70–90% of their day sedentary, contributing to rapid muscle loss, frailty, reduced functional capacity, cognitive decline, and impaired QoL. Both intradialytic and interdialytic exercise programs significantly improve aerobic capacity, muscle strength, dialysis adequacy, inflammation markers, and patient-reported outcomes. Interdialytic training allows higher exercise intensity and volume, resulting in superior gains in VO₂ max, mobility, and muscle performance. Home-based and supervised programs are feasible and safe, though adherence is limited by fatigue, depression, and access barriers.

Conclusion: Physical inactivity and sedentary lifestyles profoundly worsen musculoskeletal and functional health in HD patients. Structured exercise, particularly intradialytic and interdialytic training, provides meaningful physiological and clinical benefits. Exercise should be integrated as a core component of routine HD care to preserve function, enhance QoL, and improve long-term outcomes.

Hemodialysis, Muscle wasting, Physical inactivity, Intradialytic