Exercise For How Long?

You know some people view exercise as something temporary, kinda like being on a diet. But exercise should be done how long? I say that exercise should be done for life. Don't ever quit. Oh, your mode of exercise may change, but you keep doing some sort of exercise. And if you get where you are up in age, and you haven't been exercising, then start slow, and do something. And if you are young, and don't have any kind of weight problem and feel you have no time for exercise, start now, because you will one day have a problem. Maybe it won't be a weight problem, but you will have problems. I work in a dental office, and a couple of days ago, my first three patients were in their late 60's. I frequently ask patients not only about their teeth, but about their health and what they are doing for it. All three ( 2 males, and one female) were exercisng. The two men had been working out for years. One walked on the treadmill and worked out with weights at a local gym. The other rode a stationary bike and worked out with weights at a local gym. The lady had just begun to exercise after spending time with a sick husband who since has passed away. She walks on the treadmill. I have no idea what I will be doing when I approach 70, which will be here sooner than I would like, but I do hope that I can take these fine people's example and continue to exercise my entire life. How about you? Exercise for how long?