musclemass

Muscle mass refers to the total amount of skeletal muscle tissue in the body. It is a major component of lean body mass and plays a key role in movement, posture, metabolism, and overall strength. Muscle mass can be estimated using imaging or body composition methods such as dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), computed tomography (CT), or bioelectrical impedance analysis (BIA). In research and clinical contexts, measurements may focus on whole-body muscle mass or regional measures such as appendicular lean mass.

Muscle mass is influenced by age, sex, hormones, physical activity, nutrition, and genetics. Regular resistance training with progressive overload stimulates muscle protein synthesis and can increase muscle cross-sectional area, especially when combined with adequate protein intake. Protein recommendations for adults seeking hypertrophy commonly range from about 1.6 to 2.2 grams per kilogram of body weight per day, distributed across meals. Energy balance and recovery, including sleep, also affect gains.

Accumulated muscle mass supports physical function, metabolic health, and quality of life. Higher muscle mass is associated with better insulin sensitivity, reduced risk of frailty, and improved mobility in older adults. Conversely, age-related or illness-related loss of muscle mass, known as sarcopenia, can impair independence.

People can maintain or increase muscle mass through sustained resistance training, adequate protein and calorie intake, and adequate recovery. Special considerations apply to older adults, those with chronic diseases, and balancing training load with rest to minimize injury.