The race is a grueling one. It started in Boonsboro, then cruised along the Appalachian Trail for about 13 miles. The next 26 miles were along the C&O Canal towpath, and the last few miles wrapped up at the middle school in Williamsport.
After 8 hours, 4 minutes and 48 seconds, Lum crossed the finish line. He walked over to his family, where he bent at the waist and stretched.
"I'm sore. I got sore really early today. ... I was going to quit a couple times," Lum said. "I say every year it's my last one. (This one) might be, though. I'm getting old."
Lum's family didn't seem to think so.
"He's good at it," said daughter Emily Lum, 10.
Son Nickolas Lum, 12, said his father is "sorta" a Superman to him. Nickolas said he might think about taking up running, but "I'd have to practice a lot."
David Grimm, 44, of Hagerstown, was on his own for most of the 50 miles he ran Saturday, but for the last 20 yards, his daughter picked up the pace with him and crossed the finish line with her father.
Dana Grimm, 13, said she's proud of her father, but she has no intention of making it a family tradition.
"I'm not a runner," the younger Grimm said, squishing her face at the thought.
Laura Nelson, 39, of Woodstock, Va., graduated from South Hagerstown High School in 1983. Saturday was her 10th time running the JFK. She was the top female finisher four times before.
As she crossed the finish line, her two aides flanked her and braced her for the short walk back to their van. Nelson said she didn't feel in tip-top shape - the 13 miles along the Appalachian Trail was "by far" the hardest part.
"I was tired, sluggish," Nelson said. "I had a heck of a time on the trail today."
One reason she might not have felt her best was that she ran a 50-mile race about a month ago, and had run a 62-mile race three weeks before that.
Nelson said there were two reasons she puts herself through these types of races.
"First of all, I don't think I'm all there. Second, I like the challenge. ... I guess it keeps me entertained," Nelson said.
Nelson said she runs with people locally about once a week on the canal towpath.
Her advice to those who'd like to try this: "Be patient, and try to run a steady pace. ... Run cautiously. It's not worth your life."