Eccentric resistance training as a low-metabolic alternative to cardiotraining in patients with HFrEFf: a randomized controlled study

Abstract Background Cardiotraining and resistance training are core components of physical rehabilitation in patients with heart failure with reduced ejection fraction (HFrEF). Eccentric resistance training is a modality characterized by a lower metabolic cost compared to concentric resistance training, meaning it requires less energy expenditure and a lower oxygen demand. During eccentric loading, the muscle contracts while lengthening, allowing higher training loads. However, this modality has been scarcely investigated in individuals with HFrEF. Methods 31 Patients with HFrEF were randomized to an intervention group (n=16) or a control group (n=15). The intervention group completed a program emphasizing eccentric and eccentric overload training combined with limited treadmill-based moderate intensity cardiotraining. The control group received standard care consisting of conventional resistance training and moderate intensity cardiotraining using both treadmill and cycle ergometer. Training was performed three times/w and lasted approximately 50 minutes per session. Intention-to-treat and sensitivity analyses were performed. Primary outcomes included changes in muscular strength and exercise capacity parameters after 15 weeks training. Secondary outcomes included functional performance tests and biometric parameters. Results 4 patients were lost to follow up (one because of withdrawal because of practical difficulties, three because of medical reasons unrelated to the study design). In the sensitivity analysis, the results of two participants were excluded due to non-adherence to the intervention protocol. Both groups demonstrated comparable improvements in muscular strength and exercise capacity parameters, consistent with expected training adaptations in a cardiac rehabilitation setting (see table). Anthropometric parameters remained unchanged. No significant between-group differences were found in the intention-to-treat or sensitivity analyses. Conclusion Eccentric resistance training appears to be a feasible and effective alternative to cardiotraining in patients with HFrEF, achieving similar training outcomes while imposing a lower metabolic load. Nonetheless, individual tailoring remains essential, as patients who tolerate or seek higher metabolic challenge may not prefer eccentric resistance training as a substitute for cardiotraining.Strength evolutionFor image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text.