All good info, it's true! Don't want to hijack @TwoTankAmin 's thread though. My dad's main issue is balance, he has ulcers in one leg that haven't healed for the last three years or so. District nurses have to dress them three times a week, and he used to walk to and from appointments before the hip thing, now the nurses come to the house. But he's always been an active and fit man throughout his life, walked daily right up until he broke his hip and not one for sitting doing nothing, and that helped a lot when he did break his hip, which was an unfortunate fall sideways onto a concrete step in the garden. However, because he was so active and had strong leg/back/hip muscles from daily walks and activity, he recovered better and faster than most his age do after a hip fracture and replacement. Within a week of the op he was at home, going up and down the stairs even to reach the bathroom and bedroom, only a walker required. He walks up and down the street twice daily now, pushing himself to do more each time. I remind him not to push himself too hard, and remind him how far he's already come when he gets frustrated.Your dad needs to do weights to strengthen the muscles and bones so there is less chance of him falling over and less chance of breaking something if he does fall down. He will have more chance of getting up by himself if he does weights.
I was terrified when we found out his hip was broken, since I've worked with the elderly before, and well aware that it often means lost mobility, and a rapid downhill decline for many. I'm so grateful and lucky that it hasn't been the case for my dad, and I certainly believe that staying fit and active like you say helps to prevent injuries like that, and also helps you recover if something does happen.