Dose-Response Associations of Exercise Modalities With Cardiorespiratory Fitness in Heart Failure: A Systematic Review and Bayesian Network Meta-Analysis

Aims Exercise training improves cardiorespiratory fitness in patients with heart failure, yet the dose-response relationship across different exercise modalities remains unclear. This study aimed to evaluate the effects of different exercise modalities and their standardized doses on peak oxygen uptake (VO2peak) in patients with heart failure. Methods We systematically searched multiple databases from inception through March 2026 for randomized controlled trials comparing exercise interventions with controls. Exercise modalities were categorized as interval aerobic training (IAT), continuous aerobic training (CAT), resistance training (RT), mind–body training (MBT), and their combinations. Exercise dose was uniformly quantified as weekly metabolic equivalents (MET-min/week). A Bayesian model-based network dose–response meta-analysis was performed. Results A total of 100 trials involving 5,353 patients were included. The dose–response relationship followed an Emax curve, with ED50 values clustering around 80–90 MET-min/week. A weekly dose of 500 MET-min yielded considerable benefit, and 750–1000 MET-min approached maximal benefit for nearly all modalities. The top three ranked interventions were IAT (Emax = 3.50, 95% CrI: 2.49–4.60), RT (Emax = 3.66, 95% CrI: 1.96–5.85), and IAT+RT (Emax = 3.49, 95% CrI: 1.26–5.79). Conclusions The exercise dose–response relationship in heart failure follows an Emax curve, with distinct dose–benefit profiles across different exercise modalities. Based on the current evidence, the following preliminary considerations may be offered: for patients with limited exercise tolerance, MBT may be considered as one of the preferred options; for those with moderate exercise tolerance, IAT+RT or CAT+RT may be suitable choices; for patients with good exercise tolerance, IAT or RT may be considered; and for patients with comorbid obesity, CAT may be incorporated into a comprehensive management program.