Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, is increasingly recognized as a critical factor influencing surgical outcomes. It is distinct from frailty in its focus on muscle health and can be objectively assessed using bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA), and grip strength testing. The pathophysiology of sarcopenia involves an imbalance in muscle protein turnover, hormonal changes, chronic inflammation, and neuromuscular decline, with age and comorbidities exacerbating its effects. Globally, sarcopenia prevalence ranges from 1–29% in community-dwelling individuals to 14–33% in long-term care settings. In Singapore, nearly 90% of older adults have poor muscle health, highlighting the urgency of targeted interventions. Sarcopenia negatively affects both intraoperative and postoperative outcomes, increasing the risk of anesthesia-related complications, prolonged recovery, and higher rates of infections and mortality. It is also a strong predictor of poor oncological outcomes, impairing chemotherapy tolerance and reducing overall survival. The economic burden of sarcopenia stems from extended hospital stays and increased healthcare costs. A multimodal prehabilitation strategy, integrating resistance training, nutritional optimization, and psychological support, has been shown to mitigate these risks. Emerging therapies, including pharmacological interventions and regenerative medicine, are being explored for their potential benefits. The SUPREME program in Singapore has demonstrated that systematic prehabilitation can equalize surgical outcomes between sarcopenic and non-sarcopenic patients. As sarcopenia becomes more prevalent in aging populations, early diagnosis and comprehensive management strategies are essential to improving surgical outcomes and quality of life.