Age is pretty relative. My mom (who is now 73) has only fairly recently struck me as "old" whereas my first feeling of my dad being old was when he got his first electric scooter at like 62. Somehow, he's still kicking. He'll be 77 in two weeks.

I'm 35 and can generally run and lift circles around half or more of anyone my age or younger. I know people my age and younger who are falling apart. I also know people 20+ years older than myself who are still in pretty good shape.