Heart failure (HF) is a complicated clinical syndrome caused by structural and/or functional cardiac abnormalities that result in ineffective myocardial pumping. HF management has placed more emphasis on improving the prognostic factors which determine these poor clinical outcomes. More recently, the prognostic role of sarcopenia in HF has received particular attention. Defined as progressive and generalized decline in skeletal muscle mass, strength and physical performance due to aging, sarcopenia is definitely a common comorbid of HF which follows an age-specific disease epidemiology. Given muscle disuse is the most preventable and reversible factor of sarcopenia, more evidence points to the therapeutic value of resistance training (RT) for this debilitating condition. Nevertheless, the therapeutic effects of RT on improving sarcopenia and thereby the disease prognosis among HF patients is yet to be evaluated. Therefore, the sequential mixed method study including a pilot RCT will be conducted to evaluate the preliminary effect of a 14-week elastic band-progressive resistance training (EB-PRT) and a subsequent qualitative study to explore the subjects' engagement experience. The outcomes cover the whole set of defining characteristics including muscle mass, muscle strength and functional performance and the clinical outcomes which reflect HF disease severity and patient-reported HRQL.

The aim of this study is to investigate the therapeutic value of resistant training (RT) in improving sarcopenia in heart failure patients. To better achieve such therapeutic effects, the design of RT program also needs to comply with the exercise guideline with emphasis placed on increasing the skeletal muscle mass (i.e., the key pathological factor of sarcopenia). Addressing these research agenda is crucial to inform the development of evidence-based practice to tackle the prognostic impact of sarcopenia among HF patients. This is a sequential mixed method study including a pilot RCT to evaluate the preliminary effect of a 14-week elastic band-progressive resistance training (EB-PRT) and a subsequent qualitative study to explore the subjects' engagement experience. The total study period last for 40 weeks. The sample size is 62 participants. It is a single-blinded study. The research assistants for data collection will be blinded.

For intervention group, EB-PRT is implemented during week 1-14. A purposive sample of 12 participants invited for qualitative interview during 21st -22nd week. There are 2 post-test evaluations at 14th week (T1) and 26th week (T2). After the second evaluation at week 26, the group will receive usual care with routine follow-up. For the qualitative study on, a subsample of 12 participants in intervention group will be invited to explore their experience and perception at about 21st-22th week. The interview will be semi-structured and taken about 30-40 minutes at participants' home. The control group will receive usual care including the medical care offered by the specialist out-patient clinic during 1-26 week. There are 2 post-test evaluations at 14th week (T1) and 26th week (T2). From week 27 to week 40, this wait-list control group will receive the same EB-PRT as the intervention group.

Inclusion Criteria:

1. age ≥ 50;
2. has a confirmed clinical diagnosis of HF in the electronic health record for at least 6 months to ensure adequate disease exposure;
3. meeting the Asian Working Group of Sarcopenia's criteria2 [grip strength measured by dynamometer (Male: <28kg; Female: <18kg); low physical function (defined by Short Physical Performance Battery score ≤9) and reduced muscle mass by bioimpedance analysis (Inbody Technology 270; Male: appendicular skeletal muscular index (ASMI) <7.0kg/m2, Female: <5.7kg/m2)];
4. has stable HF and do not have any acute respiratory and musculo-skeletal condition which contradict them from practising exercise;
5. no regular resistance training for the previous 6 months.

Exclusion Criteria:

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