Multi sports Coach Paul Huddle is one of the founders and he says the run was formed back in 1998 in reaction to seeing all those athletes in Kona wearing Speedos.. and not just to swim, bike and run.
"You see them in line at the bank, at the KTA supermarket, out to dinner.. in Speedos," Huddle explains. "A couple friends and I decided to drop our pants and run down Ali'i Drive just to make fun of them."
There were three that first time, 30 the second year and every year after the numbers have grown. The race is held the Thursday before the Ironman and this year there were more than 500 men and women running down Ali'i Drive in their underpants.
Huddle says early on they realized the run could be a fun fundraiser for Big Island charities and a number of organizations have benefited. Huddle says this year they raised more than $16,000 and in total more than $100,000.
If you want to participate next year you should know the rules. "Only tighty whities," says Huddle. But he also says no one actually follows the rules and he doesn't enforce them, so you will likely see every type, size and color of underwear imaginable.
Check out the video from 2012's Underpants Run.. and good luck to all 1,900 triathletes from around the world competing this year.