The bones of the body will respond to repeated bruising by laying down or producing more calcium in that spot. Hence the painful hand training that many TMA and fighters have to do. Kick boxers and MT fighters spend many hours on just the lower leg. The bones of the hand, lower leg, feet, wrist and forearm are relatively easy to toughen and thicken, albeit a very painful and long process. The bones of the nose, well you might not want to bruse it in that way. You can strengthen the muscles of the face however. The easy nose bleed, well you might just be an easy bleeder...
