According to New York Times exercise is not a way to build stronger bones. Yes, we’ve heard many times that strength training does it all but turns out it has nothing to do with bones getting stronger (i.e. growing) but rather it has to do with stronger muscles and ligaments that can protect our bones from injury and fracture.
After looking into available research data and the findings
While exercise gives 1% or less of bone structure changes, the changes in muscle mass are much more significant and can be accounted for some bone protection. So while it doesn’t necessarily make your bones stronger exercise can still provide you with strong muscles and ligaments to protect you from injury and even bone fracture. There are also other reasons not to toss your gym membership.