Sarcopenia

What it is

Sarcopenia is age-related loss of skeletal muscle quantity and quality. The EWGSOP2 definition requires:

• Low muscle strength (grip strength or chair-rise) — the defining criterion.
• Low muscle quantity or quality (DEXA appendicular lean mass index, ultrasound, BIA).
• Optionally: low physical performance (gait speed) for severity.

Why it matters

• Muscle mass and strength independently predict all-cause mortality.
• Underlies most falls and hip fractures in older adults.
• Worsens insulin resistance, cardiometabolic risk.
• Reduces resilience to surgery, hospitalisation, and acute illness.

Risk factors

• Inactivity (the dominant cause).
• Inadequate protein intake.
• Inflammation, chronic disease (cancer, CKD, COPD).
• Hormonal (low testosterone, menopausal estrogen loss).
• Vitamin D deficiency.
• Prolonged bed rest / immobilisation.

What works

• Resistance training (the single most effective intervention; gains possible even in 90-year-olds).
• Adequate protein (1.2–1.6 g/kg/day in older adults, distributed across meals).
• Creatine monohydrate amplifies training response.
• Treat reversible contributors: vitamin D, hypogonadism, depression.
• Avoid sedentary recovery after acute illness.

Related entries

Grip strength, DEXA scan, Exercise, Protein and mTOR.