He's a sumo wrestler who proudly calls himself the Fat Man. Clocking in at 405 pounds, Kelly Gneiting aims to enter the record books at Sunday's Los Angeles marathon as the heaviest competitor in history to go the distance, the Los Angeles Times reports.

"Big people," he says, "can do the unimaginable."

Gneiting, a three-time U.S. national champion sumo wrestler, is 6-feet-tall with a 5-foot waist. Stamina is certainly a strong suit: the eastern Idaho native once ate eight Big Macs at a single sitting.

"In high school, I was 190 pounds, so I know what it is to be thin," he says. "I married my wife at 205 pounds. Suddenly, jeez, I didn't need to attract anyone. I just kind of let myself go. "

Running 26.2 miles was an aspiration of Gneiting since grade school. He actually achieved the feat at the 2008 Los Angeles marathon although the 12-hour ordeal left his feet purple with bruises -- and worst of all, he failed to notify the record-keepers beforehand.

This time, he will lumber onto a weight scale just before the starter's gun and need photographic evidence and confirmation from race officials to satisfy the Guinness Book of Records that he has finished.

After that, his goal is to swim the English Channel and hike from the Dead Sea to Mt. Everest.

Click here to read more from the LA Times.