Broken legs and ankles heal better if you walk on them within weeks

The human body (like most fit organisms) is antifragile. It needs to be challenged. In this context, people who think "ooh that hurts I'll never do that again" and carefully avoid discomfort find that, by middle age, they can't do anything, and everything hurts. Meanwhile people who think "ooh that hurts, I'd better practise it until it doesn't" are still fully functional into old age because they push their bodies in the right way, and so their bodies stay strong.

Don't get me wrong, the latter group still hurt. Getting old sucks. But their bodies work.

The right level is hard though. I know more than one old person who spent time in a hospital because they thought they could do something they couldn't and broke their bone. "For $20 they would install the new dryer, but no we thought we could do it and that is how my foot got broke in the fall". You should have a cane handy when you need one, but don't use it if you don't need it.

I have no idea how to find the right balance.

Yes and no.

Professional athletes are usually miserable later in life due to doing exactly that.

I broke my shoulder and they immediately offered me a handicapped placard.

I am the type of person to become offended at the suggestion.

I parked at the back of the lot and took the longest walk I could instead.

That has paid off.

Accidents are almost always bad, for sure. Doing things that you are physically capable of, though, is rarely a problem.

The perception of things like weightlifting being dangerous or bad for your back though are almost entirely a myth. It is possible to screw it up, but from what I've read it's very rare for people just lifting things to hurt themselves.

Absolutely. One grandmother worked as a farmer. The other worked as an book keeper. The book keeper who believed "exercise is for other people" is frail and extremely week. The farmer is also weak but is far more independent and is seldom sick.

This sort of thing starts at a WAY younger age than people imagine too. I'm 30 and used to not be able to stand up from sitting on the ground without grunting and effort.

Got a dog. Sit on the floor to play with him all the time. Can now stand up from sitting on the ground without effort or grunting or using my arms to push myself up.