Most of us don’t build muscle mass after young adulthood. After we turn 50 our muscle mass decreases 1-2% per year. From our 20s until the age of 80, our muscle mass decreases by 30 – 50%! This becomes increasingly noticeable after age 70.Our strength declines by 10%-15% per decade until age 70, when this loss accelerates to 25% to 40% per decade. Sarcopenia, or muscle loss, often serves as a harbinger of frailty. But frailty is not normal with aging. The five factors of frailty (three must be met to be considered frail): Unintentional weight loss; exhaustion; muscle weakness; slowness in walking; low levels of activity. Multiple studies show that a good exercise program, including aerobic, strength, and balance regimens, preserves muscle mass in older generations. Chapter explains how frailty is a group of symptoms that can be effectively avoided or treated.