I read this study fairly recently, it has some pretty awesome implications, like doing plyometrics to prevent osteoporosis for example could be one. We all know weightlifting improves bone mineral mass, but what about just sprinting running, and depth drops? Pretty cool.
When I first started training, I noticed I couldn't do a running 1 footed vertical because I felt like my shins would explode. I did drop jumps for like 2 weeks and the problem was fixed, so perhaps my bone density actually improved along with tendon stiffness, and other stuff... who knows.