Which of the following is a common physical change associated with aging?

Reduced muscle mass, often referred to as sarcopenia in the context of aging, is a common physical change experienced by older adults. As individuals age, a decrease in muscle strength and size is typically observed, which can significantly impact mobility, physical capabilities, and overall quality of life. This reduction in muscle mass can be attributed to a variety of factors, including hormonal changes, decreased physical activity, and a lower rate of muscle protein synthesis.

In contrast, increased bone density is not generally a change associated with aging; rather, aging often correlates with a decrease in bone density, increasing the risk of fractures. Enhanced skin elasticity diminishes over time due to a decrease in collagen production and skin hydration as people age. Additionally, while organ function can vary, many organs typically undergo some decline in function as well, making the notion of improved organ function less relevant to the aging process. Therefore, the identification of reduced muscle mass as a common change reflects an important aspect of gerontological health.