Feasibility and Effectiveness of Eccentric Exercise in Sarcopenic Older Adults with Heart Failure: a Pilot Study

Participants must meet all of the following criteria: * Age 65 to 85 years * Diagnosed with stable heart failure (HF), defined as: * Preserved left ventricular ejection fraction (≥50%) or * Reduced ejection fraction (≤40%) * Classified as New York Heart Association (NYHA) class 1, 2, or 3 * Meet the diagnostic criteria for sarcopenia or sarcopenic obesity: * Sarcopenia: Impaired muscle strength with the Five-repetition chair stand test time \>15 seconds (normal weight) or \>17 seconds (patients with obesity) * Reduced muscle mass according to the European Working Group on Sarcopenia (EWGSOP) or Sarcopenic Obesity: Based on the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO). * For EWGSOP: Sarcopenia as Class I: Skeletal muscle mass index (kg/m²) * Males: ≤10.75 kg/m² * Females: ≤6.75 kg/m² * For EWGSOP: Sarcopenia as Class II: Skeletal muscle mass index (kg/m²) * Males: ≤8.50 kg/m² * Females: ≤5.75 kg/m² * For ESPEN-EASO: Obesity: waist circumference calculated in centimeters (cm) * Males: ≥102 cm * Females: ≥ 88 cm Sarcopenia as Class I: Skeletal muscle index as a percentage of body weight (%) * Males: 31.3-37% * Females: 22.1-27.6% Sarcopenia as Class II: * Males: \<31.5% * Females: \<22.1% Exclusion Criteria: Participants will be excluded if they meet any of the following conditions: * Severe obstructive heart disease * Aortic valve stenosis * Severe arrhythmias identified during initial stress testing * Intracavitary thrombosis * Severe pulmonary hypertension (\>70 mmHg) * History of venous thromboembolism within the previous three months * History of heart transplantation * Medical conditions that significantly limit functional capacity beyond the impact of HF