Nobody "just dies". Most "natural deaths" are still heart failure. The rest are other kinds of organ failure.
For a lot of people that die natural deaths they could have lived longer if they had kept fit. It just gets really hard to either do or justify when everything hurts and gets harder to do year over year. Or when you are confined to a wheelchair since your early 20s, were told you would only live two years, and then beat that prognosis 27 times over.
But if you are able, even small amounts of cardio exercise could dramatically extend your health and lifespans in old age.
It's true that an autopsy will show a cause of death for anyone. In that sense, you don't "just die".
But after a certain point, that cause of death starts looking pretty meaningless. Everything is failing at once; if you hadn't died of your actual cause of death, you would have died shortly afterwards from another one. In that sense, you do "just die" of old age.
For a lot of people that die natural deaths they could have lived longer if they had kept fit. It just gets really hard to either do or justify when everything hurts and gets harder to do year over year. Or when you are confined to a wheelchair since your early 20s, were told you would only live two years, and then beat that prognosis 27 times over.
But if you are able, even small amounts of cardio exercise could dramatically extend your health and lifespans in old age.