What sarcopenia is
Sarcopenia is the progressive, age-related decline in skeletal muscle mass, strength and physical performance. It typically begins around midlife and accelerates after age 60, and it is now formally recognised as a diagnosable condition rather than an inevitable part of ageing.
Why it matters for longevity
Muscle is not just for movement: it underpins metabolic health, balance and independence. Low muscle mass and weak grip strength predict falls, disability and mortality, and sarcopenia frequently overlaps with frailty. Because it is measurable and treatable, it is one of the highest-leverage targets in preventive longevity care.
What the evidence shows
Progressive resistance training is the best-established intervention, reliably increasing strength and function in older adults. Adequate protein intake supports these gains, and correcting deficiencies (vitamin D, physical activity) helps. Drug therapies remain investigational.
How it's assessed
Clinics typically combine a muscle-mass measure (DXA or bioimpedance) with a strength test (grip dynamometry) and a performance test (gait speed or VO2 max).
Bottom line
Sarcopenia is largely preventable and partly reversible — resistance training plus sufficient protein is the evidence-backed core.