Muscle Preservation During Aging

Sarcopenia begins at age 30, accelerating after 60 with 3-8% muscle loss per decade, but resistance training is the only intervention proven to reverse this decline. A 2013 systematic review found that 12 weeks of weight lifting increased muscle fiber cross-sectional area by 31% in seniors, whereas excessive endurance cardio without strength work can accelerate muscle wasting by 5-10% annually. Hypertrophy is not vanity; it is metabolic insurance against frailty and metabolic slowdown.