So I am 45, about to be 46. My father is 83. He is pretty far along with dementia, is in a VA home in Alabama, and nearly died, but that was due to being in a really bad state care facility prior that seemed to prefer to drug and leave their patients in a room to die rather than take care of the difficult ones. He recovered well, and is physically doing good, which ain't bad for having been on life support. He has been physically active his whole life, is strong, and I think that is part of the reason for his recovery.
So rounding back time to maybe about 75 for dad, and matching him to me, I have 30 good years left to do things before that downward slope to mortality. I have been aiming to be more physically fit: lift weights 2-3 times a week, run 2 times a week, and walk 4000 steps a day, and it shows. And aside from being more fit now, these are the things that correlate with a bonus of about +5 years of life, and probably a much slower downhill fall into old age weakness.
My father-in-law (well x-father-in-law) who had a serious sky diving crash and who didn't look like he was ever going to walk again, now is starting to walk with a walker, and I attribute that to the fact that he is fit and always lifting.
Strength training isn't so much for ascetics for me (I got all I need from my good looks with my beautiful wife) but sticking around and being someone my kids can look up to and their kids as well. I also keep myself interested in my millions of distractions and keep my brain as sharp as I can.