Iron fist/body conditioning is the same, Your only speeding up the process by conditioning. Remember its not ment for everybody & those who truly do not understand. I found a link for those of you interested in bone conditioning, heatlh etc...
http://health.yahoo.com/health/centers/bone_health/912 "On the other hand, each time your feet hit the ground in an activity such as jogging, jumping, or tennis, your skeleton withstands impacts three to six times greater than your body weight. The greater demand on your bones is met with a matching increase in bone mass"
So in my experiance everytime you hit your fist or let me get something everyone has probally done like banging your toe on the bedpost at night going to the bath room, is what i concider conditioning.