Bennett Beach isn't as fast as he once was, and he's dogged by a painful disorder that makes running difficult, but he's still the Iron Man of the Boston Marathon, getting set to complete his 48th straight race

In 1968, Harvard freshman Bennett Beach ran the Boston Marathon. He admits now that he didn't really know what he was doing and was ill prepared. So, he came back the next year to see if he could do better. And then he returned every year since. Beach now holds the record for consecutive Boston Marathons completed. This year, he'll try to complete his 48th straight. My story for ESPN.com's Endurance Sports section: http://www.nbcbayarea.com/news/sports/Niners-Cornerback-Competition-Could-be-Fierce-299697231.html