Feet pounding pavement again and again have given Cartledge a strong heart.
But it's his big heart that brings him and at least a dozen officers out to Layer Elementary each week.
Two, three, even four times a week, Cartledge runs a mile. He runs for Central Florida officers killed in the line of duty.
And he's run for hundreds of other first responders who have died, too.
“There was over 50, I think, that passed away from gunfire, so I really wanted that to stop,” Cartledge said. “So I decided to run in honor of not just one officer, but every officer.”
Agencies from around the world send uniform patches to Cartledge as they learn about his mission.
As of Monday night, he's run 295 miles for those killed this year and last.
And Cartledge has gotten twice that many patches, pins, cards and insignia from the officers' agencies and families, some of whom he's never met.
"The officer or the firefighter's family that I run for, they say that this is their only happiness through their hard time and because of me, they're still holding on to hope," Cartledge said.
After each run, Cartledge sends the thin blue line flag he ran with and a note to the family of the fallen first responder.
He said one day he hopes there will be more time between runs.