Explaining the Chris Legh Gatorade Commercial

Ever wonder what really happened to Chris Legh in that now ubiquitous Gatorade commercial? (Miami Herald registration required). "It's spine-chilling stuff, a mix of horror and inspiration -- especially when you learn that the footage is real, shot at the 1997 Ironman Triathlon in Kona, Hawaii." Says Legh:

`I thought if I just shut my eyes and made it to the end, I'd be all right. I came up about 50 meters too short.''