The thing of it is, while there are no guarantees in life, there are some very basic movements that can really improve one's odds. They don't require one to be young, strong, or an athlete - though all of those factors could be useful.
+1 to this. I wrestled a couple years back when I was in high school and the one thing I took out of it was that technique trumps size. I have seen some small 140lb wrestlers take down guys that outweighed them by 50lb's like it was nothing. Sure size and strength helps, but if you don't know how to use it, it only helps so much.