I'm female, and pretty freaking old. I used to play ice hockey, run daily, and skied like a maniac. I still ice skate and generally keep in shape. The best advice I can give for people in my age group (70 plus), is to never stop exercising. It doesn't have to be anything crazy, but should be consistent. All I do is a combination of stretching, core work, and half-assed yoga. Use it or lose it is my motto. Edit to add: I started taking vitamins and supplements in my early thirties, and still do.