## 1 Introduction  
Heart failure (HF) is a complex and debilitating cardiovascular syndrome, with its incidence and prevalence rising annually due to changes in lifestyle [1,2]. Based on ejection fraction and functional impairment, HF is categorized into heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) [3]. Although these two types have different etiologies, they share highly similar clinical manifestations, such as reduced exercise tolerance, impaired neurohumoral regulation, and diminished cardiac pumping capacity [4, 5, 6]. Despite the availability of various pharmacological and non-pharmacogical treatment strategies, patients with HF still experience exercise intolerance, excessive sympathetic activation (which is associated with poor prognosis), and reduced quality of life (QOL) [7,8]. It is alarming that over 23% of HF patients are rehospitalized within 60 to 90 days [9], and the survival rate is only 59% five years after the diagnosis of HF [10]. Reduced exercise capacity is a hallmark of HF patients, which can be attributed to factors such as endothelial dysfunction, decreased cardiac output, and autonomic nervous system dysregulation [11]. Exercise rehabilitation, as a non-pharmacogical treatment approach, has been proven to be effective in reducing mortality and hospitalization rates among HF patients [12, 13, 14]. Exercise training offers numerous potential benefits, including improvements in peak oxygen uptake (VO2 peak), central hemodynamics, peripheral vascular and skeletal muscle function, autonomic nervous system function, and overall functional capacity [15]. The European Society of Cardiology (ESC) guidelines recommend that HF patients engage in regular physical exercise, as it may help alleviate cardiac and muscular dysfunction [16]. Studies have demonstrated that exercise improves QOL by reducing sympathetic nervous excitability, enhancing vagal nerve activity, improving autonomic nervous function, and increasing aerobic capacity [17, 18, 19, 20]. Additionally, exercise improves skeletal muscle endothelial function by enhancing peripheral blood flow and increasing the systemic arteriovenous oxygen difference [21], thereby enhancing aerobic capacity, reducing rehospitalization rates, and improving QOL [22,23]. Some researchers argue that improvements in aerobic capacity are primarily driven by peripheral adaptive changes, such as enhanced efficiency of oxygen delivery to active muscles [24], which also increases the potential for peripheral exercise training to improve exercise tolerance. However, not all studies support the positive effects of exercise on HF patients. For instance, a study by [PERSON] et al. [25] found that supervised training over three months did not improve VO2 peak in HF patients. Similarly, another study focusing on elderly HF patients found that a six-month exercise program did not result in the anticipated improvements in VO2 peak or six-minute walk distance [26]. These conflicting results may be related to the type of disease, the age of the subjects, and the specific exercise protocols employed. Previous systematic reviews have shown that exercise-based cardiac rehabilitation improves QOL in HF patients compared with the control group that do not engage in exercise [27, 28, 29]. However, these reports have limitations. First, previous studies have primarily focused on patients with HFrEF. Given that HFpEF patients also experience exercise intolerance similar to that of HFrEF, the efficacy of exercise interventions in HFpEF warrants further investigation. Second, some studies only emphasized center-based rehabilitation, ignoring the potential benefits of home-based rehabilitation programs. Finally, the heterogeneity of the control group (e.g., inclusion of other exercise interventions) introduces uncertainty into the observed effects of the intervention. Therefore, the comprehensive impact of exercise on HF patients has not yet been fully assessed.