Exercise, good diet and lifestyle choices like calorie restriction have an enormous impact on the health you'll have later in life. While it most likely won't extend your maximum possible life span, avoiding cutting your health and life span short increases your chances of living to see working anti-aging medicine capable of repairing the cellular damage that causes aging - and thus enjoying a life of good health for even longer than you expected. Via the BBC, here's another reason - amongst the many - to take better care of the health basics: "The study of people aged between 43 and 86 began in 1988 and they were assessed every five years. ... after taking into account other risk factors such as weight, blood fat levels and age, active participants were 70% less likely to develop [age-related macular degeneration, or AMD] than those who did little exercise. It also showed regular walkers were 30% less likely to get the disease." Healthy is as healthy does: it isn't rocket science.