i think i read in one of my wife's books that pregnancy shrinks a woman's brain. reproducing must be bad for you also. This all sounds like a pile of BS. Any pure athlete is using up their body. Pro football players die of various ailments early too. So running into each other at full speed must be bad too? Duh
The one thing I've noticed from riding longer distance is my hand strength is greatly diminished and I've only been back into riding for about a year.