My parents and my in-laws are in their 60's, which doesn't seem all that old once you hit your 30's like me. When I look at them, I see old people who can't do much of anything active any more because they have allowed their health to slide. Like the vast majority of people, they haven't actively pursued good health during their lifetimes, and now they think that its too late for them to do anything positive about their failing bodies.
On the other hand, I know two gentlemen in their 80's/90's who are still as active as they want to be. They run, play tennis, ski, exercise, and do anything else that they want to do. The reason they are able to do these things is because when they were younger they took steps to ensure they would be able to live they lives they wanted.
About 3 years ago, I was having some minor age-related health issues, and I really thought a lot about those two old guys. I came to the conclusion that I wanted to be in their group, and not the group in which my parents find themselves. I decided I was going to change my life and make myself as healthy as possible. Following this decision has brought me nothing but rewards and benefits.