This study is designed to evaluate the safety, feasibility, and effectiveness of a 12-week eccentric exercise program for older adults with sarcopenia (muscle loss) or sarcopenic obesity and chronic heart failure (HF). The program aims to improve physical performance, muscle strength, and overall health without causing excessive strain on participants. Eccentric exercise has shown potential benefits for improving muscle function, and this study will help determine if it is a safe and effective option for individuals with heart failure and muscle loss. Study Goals: The primary aim of this study is to test the feasibility and effectiveness of an eccentric exercise program for older adults with sarcopenia and CHF. The study will monitor physical performance, adherence to the program, and participants' ability to tolerate the exercise, as well as any impact on heart and muscle health. Study Population: A screening visit will be scheduled to determine if individuals meet the criteria to participate in the study. During this visit, a detailed assessment will be made, and if eligible, participants will sign an informed consent form. This study will assess whether a 12-week eccentric exercise program can help improve muscle strength, cardiovascular health, and overall physical performance in individuals with HF and sarcopenia. The program will involve exercising on an eccentric bike, which is designed to reduce strain on the heart while providing effective muscle strengthening benefits. The study will use several physical performance tests to assess the impact of the exercise program, including: 1. Short Physical Performance Battery (SPPB): Evaluates mobility and strength. 2. 6-Minute Walk Test (6MWT): Measures cardiovascular fitness. 3. Handgrip Strength and Leg Strength Tests: Assess upper and lower body muscle strength. 4. Additionally, body composition will be evaluated using tools such as DXA scans and bioelectrical impedance analysis (BIA) to measure muscle mass, fat, and overall health status. The program's adherence and tolerance will be carefully monitored by measuring session completion, intensity, and participant feedback. Primary Outcomes Feasibility Measures: 1. Recruitment and Completion Rate: The ratio of participants recruited to those who successfully complete the study, including post-intervention assessments. 2. Session Attendance: The number of training sessions attended out of the total planned sessions. 3. Adherence to Training Volume: The number of prescribed exercises completed by participants compared to the total planned. 4. Program Tolerance: Evaluated by comparing the Rate of Perceived Exertion (RPE) during sessions to the target RPE. To be considered feasible, the study must meet these criteria: Recruitment \>50%, Follow-up loss \<20%, Median attendance at training sessions \>80%, Median adherence to prescribed volume \>75%, Tolerance to RPE \>70%. Secondary Outcomes Effectiveness Measures: 1. SARC-F: A tool for identifying individuals at risk of sarcopenia, based on self-reported issues like weakness and difficulty walking. 2. Mini Nutritional Assessment (MNA): Evaluates nutritional status to rule out malnutrition, which could affect training outcomes. 3. Mini Mental State Examination (MMSE): Assesses cognitive function. 4. Minnesota Living with Heart Failure Questionnaire: Evaluates how heart failure affects daily life. 5. International Physical Activity Questionnaire (IPAQ): Measures physical activity levels at baseline. In addition to the physical performance tests mentioned, the study will assess muscle mass and fat distribution using DXA scans and BIA, providing a comprehensive view of body composition. Finally, the feasibility of remotely monitoring patients' physical activity to determine the impact of the intervention on their daily lives, specifically in terms of mobility and autonomy is assessed. To this end, patients will be asked to wear a set of five sensors (two on the ankles, two on the wrists, and one on the waist) for at least four days. The Axivity AX6 sensors, chosen for their light weight and long battery life, will collect data used to monitor time spent moving, sitting, and lying down, as well as to assess the quality of the recorded movements.