Kelly Preletz ran with her son Chalie, 16, daughter Maggie, 13, and other relatives and friends in honor of Preletz's late husband.
Chuck Preletz died of leukemia five years ago, and running 5Ks, 10Ks and half marathons became a way to honor his memory, raise money, and bond as a family.
At first, Kelly Preletz wasn't a fan of running.
"I hated it," she said. "It's really tough to get out there."
"But when I finished the first one, it was like, 'We're going to be OK.' "
Although the group trains together, they diverge soon after the start line. "The boys are way faster than me now," Preletz said.
Mark Young, 33, walked hand-in-hand with his daughter Ava, 7. They had come from North Carolina to cheer on Young's girlfriend.
"Do you think we'll be able to see her?" asked Ava, in a pink leopard cowboy hat with a cowbell clanking around her neck.
"We'll see her," said Young, a Marine. "You'll be up on my shoulders soon."
Laura Winters, 31, of West Chester, said this is her third time running the Philly Rock 'N' Roll Half Marathon.
Unlike many serial marathoners, she said, this is the only race she runs. "There's no need to run with music, and so much to look at."
Kyle and Dan Barton, 34-year-old twins from Washington, D.C., cooled off after the race with a beer and a foot soak in one of the side fountains at Eakins Oval.
Their favorite part of the course is "running along the river, and you can see runners on both sides," Kyle Barton said. "It's pretty unique."
They've had plenty of time to study the route, having run this race 15 times.
"It's become a tradition," said Kyle Barton.
"He beat me. He usually does," said Dan Barton.
Contact Jessica Parks at firstname.lastname@example.org, 610-313-8117, or follow on Twitter @ JS_Parks.