As a person ages, there are many physiological changes that occur. These changes start when the person reaches the teen years, and involve all body organs. Often the first body organ affected is the musculoskeletal system. The sensory organs of the eyes and ears tend to change mid-life. As a person becomes elderly many of the internal body organs decline and begin to fail. There are risks associated with aging related to falling and other complicating factors. As a person ages, the body’s reserves are less. This is part of normal aging. At the same time, aging doesn’t necessarily refer to an old person, to someone who is unable to participate in strenuous physical activity nor to someone who can’t tolerate environmental stressors. Body changes are a normal part of aging, and there are numerous expert studies on how these changes affect various individuals based on their individual health states. A case study of the elderly involved in endurance activities is discussed.