Not to get too far off topic, but there is a difference between the effects of exercise, even very strenuous exercise, and the damage caused by accidents - which includes the damage caused by competitive sports like football, rugby, hockey, and similar, where the players inflict serious injury on each other. Being tackled or hit with a hockey stick is NOT exercise, nor is landing too hard after a parachute jump.
I have a few minor bone problems, too, but they weren't caused by exercise, they were the result of getting hit by a car.
I'm sorry. I realize that I left out the part of the story involving him humping his 60# pack all OVER THE DESERTS of the Middle East, here in the states (Ft. Bragg), & elsewhere, for the five years that didn't involve his injury/subsequent recovery time of about a year. That was part of what I meant by he and his buddies, and the fact that all of them, being infantry, walked miles and miles daily, carrying very heavy packs, and he/they all have significant breakdown at FAR TOO YOUNG an age!
Thanks for letting me clarify, though yes, definitely off topic mainly...sorry OP!
Re: our OP...what are your thoughts about all of this? Plan? Has this conjecture, ad nauseam, been helpful to YOU and your question at ALL?
Gosh I sure hope so, what with all the finger flapping WE'VE gotten out of this! :0) Thank you, OP!