Cardiac rehabilitation (CR) patients present characteristics that exacerbate their cardiometabolic (CM) risk, such as higher frailty and anabolic resistance (1). There also seems to be a link between higher mortality and low body mass index (BMI) in this population, known as the “obesity paradox” (2), which may be primarily due to low lean body mass (LBM), and in some cases sarcopenia, a progressive loss of LBM associated with aging (3). Patients presenting simultaneously low LBM and abdominal obesity (sarcopenic obesity, SO) have increased CM risk. Current CR practice is primarily focused on aerobic exercise, combined with dietary and lifestyle advice to improve cardiovascular fitness. We hypothesize that increasing relative LBM is an appropriate target in CR patients, achieved through a combination of resistance training and higher protein intake in order to overcome anabolic resistance (5). In addition, Mediterranean-style dietary patterns are effective for the primary and secondary prevention of cardiovascular disease (4). Therefore, we propose a pilot study to investigate the prevalence of SO in CR patients, and to assess the feasibility and efficacy of an intervention based on a high-protein, Mediterranean-style diet combined with resistance training to improve LBM and reduce CM risk. Firstly, a cross-sectional study will analyse body composition and estimate the prevalence of SO in CR patients. Secondly, a pilot randomised controlled trial (12 weeks) will be performed with CR-SO patients assigned to four groups: 1) control group receiving standard CR, 2) resistance training group, 3) high-protein diet group, and 4) combined resistance training and diet group. Primary outcomes will be determinants of the feasibility of the protocol for a larger, fully powered study. These will include standard deviations of secondary outcome measures (selected biomarkers of CM risk), willingness of participants to be randomised, number of eligible participants, follow-up rates, acceptability of dietary and training protocols, adherence and compliance rates, time and finances needed to implement the intervention. Secondary outcomes will be changes in LBM and body fat assessed by dual-X-ray densitometry (DXA) and bio-impedance, muscle strength indicated by hand grip, and changes in CM risk markers (e.g., blood lipids, cholesterol subfractions, fasting glucose and insulin, and HbA1c). The results of this study have the potential to inform current CR practice