An interesting review paper connecting a few previously published links in the chain: "Aging is inevitably associated with a progressive loss of muscle mass and strength, a condition also known as sarcopenia of aging. Although the precise mechanisms underlying this syndrome have not been completely elucidated, recent studies point toward several key cellular mechanisms that could contribute to age-associated muscle loss. Among these, mitochondrial dysfunction and deregulation of apoptotic signaling have emerged as critical players in the onset and progression of sarcopenia. Interestingly, calorie restriction, a well-known antiaging intervention, and, more recently, exercise training have been shown to beneficially affect both mitochondrial function and apoptotic signaling in skeletal muscle from young and old animals. Preliminary observations also indicate that even a small (8%) reduction in food intake may still provide protective effects against sarcopenia and cellular remodeling in aging skeletal muscle, with the advantage of being more applicable to human subjects than the traditional 30-40% restriction regimen." This is the era of understanding - at the deepest level - why good health practices extend healthy longevity.