Anne Mahlum is a 27-year-old marathoner. And on her predawn runs in Philadelphia, she kept passing a group of homeless men.

"They would say, 'Hi' or they would say 'Hi Anne' or 'There's the crazy runner.' 'How many miles are you doing?'" Mahlum recalled. "And they would smile and sort of applaud and cheer for me, while I would start my day."

But one day in May, Mahlum said, "I looked back, and I was like, 'I am cheating these guys. Why am I just running past them and leaving them there?'"

"Running is so simple you know. You really only need a pair of shoes. You don't need a lot of equipment. You need heart and dedication," Mahlum said.

Anne thought to herself, "Maybe running could make these guys feel as good as it makes me feel."

So she decided to start a running club for the homeless and started asking businesses for help.

"I sent out an e-mail to...