Do you train a martial art that is primarily a striking art?
If so, how often do you hit things? Your bone density and your pain tolerance will only increase if you hit things.
If you do not want to practice hitting things then take up dancing.
I am using a thick rubber exercise ball filled with 8 pounds of sand as a fist conditioning method as well as practicing head movement.
On to heavy leg kicks and some bat or baton training to soften the bag up.