So let me get this right: if you don't exercise your bones, nothing happens until you get old when your bones get brittle anyway? If that were the case, astron

So let me get this right: if you don't exercise your bones, nothing happens until you get old when your bones get brittle anyway? If that were the case, astronauts wouldn't experience any change in bone density. Let's go to the tapes: https://en.wikipedia.org/wiki/Spaceflight_osteopenia https://en.wikipedia.org/wiki/Spaceflight_osteopenia Bones get stronger where they're subjected to stress. If you don't stress them, they get weaker. If you stress them too much, they break. Put another way, you're arguing that Hafþór Björnsson, the strongest man in the world, a dude who deadlifted 1,100 lbs, has bones with the same tensile strength as a sedentary man of the same age? Or somehow you've argued that Hafþór's femurs will actually be weaker because of microfractures? LOL