Its' pretty hard to train one thing in isolation, when doing weight training you are:
Making your bones denser, strengthening the muscles and tendons.
Any activity you do tends to work multiple things and since we never really do just one thing, we tend to cover it all, using weight lifting as an example, as we see above it strengthens all that but because we also stretch the area being worked, we hit the ligaments as well.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !