CHICAGO (CBS) – About 200 people clad in little more than bikinis, Speedos and running shoes ran from Division Street, down Rush Street and back up Michigan Avenue Saturday — all in the name of diabetes research.

It’s the third consecutive year for the Santa Speedo Run, which doubled in size from a year ago.

“This time last year it was about 15 degrees colder. It snowed last year about seven inches in the morning, but we’ll take what we can get,” said a man named Nathan, who wore only shorts. “We’re having fun. It’s all for a good cause, so why not?”

Will Blodgett of Lakeview said he felt no pain leaving She-nannigan’s bar, at 16 W. Division St., which was the gathering point and the scene of the after-party. Returning, he said he was awake again.

“Those people are crazy,” said one man who chose to remain anonymous. “It is fun. I believe it is fun. But they’re crazy anyway.”

Not everyone was buff or beautiful, but a woman named McKenzie, who watched from a Rush Street salon, said that didn’t matter.

“Awesome,” she said. “It’s Christmas spirit in the street. It’s amazing. Maybe not unbuff but totally in the spirit. That’s what makes up for the unbuff.”

Many of those running carried signs proclaiming themselves as supporters of diabetes research, and North Sider Scott Hutmacher said that eliminated any sting from being under-dressed on the Magnificent Mile.

“It’s a fundraiser. It’s systematically inappropriate,” he said. “It’s a Saturday afternoon. So what else do you have to do?”

And what did he have to say to those who stood slack-jawed walking out of Michigan Avenue stores?

“I’m sorry. I’m sorry. The whole way, I’m sorry,” he said, with a grin.