Yet another study, summarized in this article by Reuters, indicates that adults who exercise moderately are less likely to die than those who don't. A sedentary life style---more so than risk factors associated with age or cardiovascular disease---significantly increased a person's chance of death. Also of note was that recent exercise was important because most people in the study had similar amounts of exercise through their adult lives. Recommended exercise is 30 minutes of an activity such as brisk walking, 5 days per week.