Had right knee tkr at 49. Did a 70.3 at just under 4 months, swim and bike were pretty normal and was able to “kinda briskly walk†the run, but it wasn’t pretty. I’m 15 months out and three more 70.3…Could I run, sure. Muscles, bone all strong enough. But I choose not too. I want it to last, and to me running would just degrade the implant prematurely. I can race the swim, the bike, and trying to get a fast walk down to what my absolute slowest jog was pre surgery.