What is the effect of aging on skeletal muscles?

With aging, the amount of connective tissue in muscle increases and the amount of skeletal muscle tissue decreases, thus the muscles become stringier (more sinewy). Since skeletal muscle represents a larger portion of body weight, it begins to decline in elderly persons as this normal loss of muscle mass occurs. Another result of the loss in muscle mass is a decrease in muscle strength–strength decreases by about 50% by the age of 80. Regular exercise can help offset the effects of aging on the muscular system, and frail elders who begin to "pump iron" can rebuild muscle mass and significantly increase their functional strength.