My greatgrandmother and grandmother lived to be 100 and 95 respectively. The most they lifted on the farm was a dozen eggs and throwing out the hot dish water which I recollected would weight about 5 pounds.  My mother who is strong at 88 and apart from falling a dozen times is quite well for 88  She has a ways to go.  
Tiger Woods with those bulging biceps and thighs cants swing a club at his age while the normal guys, Freddie, Vijay and Phil with normal bods are going strong in their 40s and 50s.
Jim Fixx the runner '.....dead at 52

I saw the great running back Earl Campbell crippled at 50...but probably from thinking he was immune from being so big and fast from playing such a goofy game.
Moderate exercise with mild resistance is good.....going to the gym staring at yourself in the mirror while self reflecting your 80 IQ no so.