"So lets say I want to do ironman's after my surgery. Is there a way that the Dr. could periodically xray my implant and measure the wear or lack of wear during training to see if infact running is detremental to the BHR? Is there a way to measure this?"
Man, I so understand this. I was set for IM AZ in 2009 before this hip deteriorated. There probably has to be a balance in here somewhere, but consider also what you would lose by not doing an IM. You can make your new hip last forever by never getting out of bed, but to what end? I would plan on it and let the chips fall where they may. If you end up with a revision to a THR several years down the road, you at least got some mileage out of your BHR, more than you can get out of your existing hip.
Strictly my opinion, of course. While I plan to live forever I'm at the age - 58 - where the occasional friend or acquaintance is dying. While I am past the need to do an IM, I NEED to jump off the cliff at Palisades in Squaw Valley, at least once.