Physiological, Nutritional and Technological Approaches to Assessing Sarcopenia in Older Adults

Sarcopenia is an age-related progressive decline in skeletal muscle mass, strength, and physical performance that increases the risk of falls, disability, and reduced quality of life among older adults. Its pathogenesis is multifactorial and involves chronic low-grade inflammation, hormonal disturbances, insulin resistance, and mitochondrial dysfunction, leading to an imbalance between muscle protein synthesis and degradation. The aim of this study was to summarise current knowledge regarding the mechanisms underlying sarcopenia, contemporary diagnostic methods, and the effectiveness of modern nutritional and exercise-based strategies, with particular emphasis on technologies supporting patient monitoring. This study is a structured narrative review conducted across PubMed, Scopus, and Web of Science databases, with the literature search completed on 1 March 2026. Separate searches were performed for thematic sections, including pathophysiology, diagnosis, physical activity, nutritional interventions, plant-derived compounds, and digital health technologies. While the core search focused on publications from 2023–2025, specific time-bound deviations were applied: the search for plant-derived compounds was extended back to 2020, and combined interventions were searched up to March 2026 to ensure the inclusion of the most recent evidence. The review included 53 peer-reviewed primary studies (RCTs and observational) and secondary literature (reviews and meta-analyses) involving individuals aged ≥60 years. The most robust evidence supports multicomponent interventions, particularly the synergy between resistance training and adequate protein intake (1.2–1.5 g/kg/day), often supplemented with leucine, vitamin D, omega-3 fatty acids, and creatine. Such strategies effectively counteract anabolic resistance by combining mechanical loading with the stimulation of the mTORC1 signalling pathway, leading to significant improvements in muscle mass, strength, and physical function. While isolated protein or micronutrient supplementation shows limited effectiveness in the absence of exercise, their role as supportive elements in multimodal strategies is well-documented. Furthermore, emerging digital health technologies—including wearable sensors and telerehabilitation—are proving essential for clinical practice, enabling precise, continuous monitoring of physical activity and gait parameters under free-living conditions, which enhances both patient adherence and long-term therapeutic outcomes.