I just completed a 70.3 yesterday in preparation for an ironman race in two weeks, which will be my second 140.6. I totally agree with all that has been said. One more important part of such endeavors is the humbling nature of the experiences. As leaders we often find ourselves in influential positions which, at times, can feel hierarchical; we are "at the top."  When one completes in such events, just getting through the day as a mid-pack athlete (like me) reminds me that I am one of the crowd, no better than anyone else. These events are truly humbling for me and help me keep my feet firmly planted on the ground. To be an effective leader, one should be as egoless as possible. Endurance events help this. I ran a 100 miler two years ago and had to walk much of the last 25 miles. My ego was left somewhere around mile 50! Thanks for listening.