I would say it has to be a few things to focus on. Staying active. , still eating right, sleep being the proper amount and quality, activities you enjoy and time with family and friends. Those are for mental health well being and connection.
I see this is a pretty old thread, but I'll respond anyway...
The focus of someone turning 70 will depend on their health and state of mind. I'm 69 and I do pretty much what I want to do. I have a whole list of hobbies, including woodworking, leatherwork, gardening, reading, working puzzles, coloring, and pretty much whatever strikes my fancy. I drive and go wherever I want to go, including driving across country if the urge strikes me or the need arises.
I do all my own housework, laundry, yard work, etc and a lot of my own household repair projects (as long as it's something I know how to do...lol).
Hobbies help keep the mind/memory sharper and help us focus better. Spending time with family and friends is also important. Social activities help prevent loneliness and keep depression and anxiety from getting a foothold.
I agree that it's important that we eat right and get plenty of exercise... I try to get out and walk every day in addition to my house and yard work that qualifies as exercise.
The bottom line is that age is really irrelevant. We can do whatever our physical and mental abilities allow us to do...