The Value of Exercise
Every year you can extend your natural healthy longevity is a year more for the scientific community to develop working rejuvenation medicine. Regular exercise certainly helps, but be wary of hype like "chop a dozen years off the biological age." Exercise is not proven to do any such thing, but it does make some biomarkers of fitness return to the levels of a person 12 years younger. Exercise also helps to avoid damage caused by a sedentary lifestyle through a variety of processes, varying from dropping excess visceral fat to changing the regulation of metabolism: "aerobic fitness may indirectly delay dependency by preventing other conditions that are likely to diminish functional capacity, including obesity, diabetes, hypertension, myocardial infarction, stroke, some forms of cancer, and osteoporosis. Exercise also hastens recovery from injuries and any additional muscle power may prevent falls, he said. ... There seems good evidence that the conservation of maximal oxygen intake increases the likelihood that the healthy elderly person will retain functional independence."
Link: http://www.medpagetoday.com/PrimaryCare/ExerciseFitness/tb/9080