Unraveling the Cardiorenal Nexus　― Emerging Frameworks and the Role of Exercise Therapy ―

Background: Chronic kidney disease and cardiovascular disease (CKD-CVD) frequently coexist, creating challenges to prognosis, exercise capacity, and quality of life (QOL). CKD is common across cardiovascular conditions, underscoring the need for comprehensive management. Newer concepts of cardiovascular-kidney-metabolic syndrome (CKM) and chronic cardiovascular-kidney disorder (CCKD) emphasize shared risk factors and interconnected pathophysiological mechanisms. Within this paradigm, exercise therapy has emerged as a promising intervention to improve exercise capacity. Methods and Results: This narrative review synthesizes conceptual advancements in the CKM-CCKD frameworks and summarizes recent literature on exercise therapy within these frameworks. The CKM-CCKD frameworks highlight the importance of addressing common risk factors and mechanisms underlying CKD-CVD. Exercise therapy comprising individualized aerobic programs is being increasingly recognized for its potential. However, its effectiveness can be limited by factors such as anemia, which correlates with impaired peak oxygen uptake and anaerobic thresholds in patients with renal dysfunction. Tailored regimens addressing reduced capacity, multimorbidity, and psychosocial factors, including patient-reported outcomes, further support inclusivity and effectiveness in clinical practice. Conclusions: Within the CKM-CCKD frameworks, exercise therapy represents an important strategy to target shared risk factors and mechanisms in CKD-CVD. Future work should emphasize evidence-based interventions, early implementation, and individualized approaches to strengthen the translational value of these frameworks and improve QOL in this high-risk population.