He has counted every mile he's ever run.
"I started my first running log in October of 1970, and I've kept every one," he said. "I told you I was a geek."
As of this morning, he has run 99,987 miles. He expects to hit the 100,000-mile mark - 6.5 miles on average every single day for 42 years - right around Boat House Row, one of his favorite places, about the midway point in the 26.2-mile race.
"I will probably let out a little whoop," he said, "but not a big one. I'll still have 13 miles to go."
Fanelli, 56, lives in California. He could have chosen any marathon to mark this milestone, but he had to come home, where it all began, where so much of his family still lives.
He ran 3 hours and 36 minutes in that first marathon 40 years ago. His best is 2:25. Today he's just hoping to savor every step, although 3:30 would be sweet.
Fanelli joined the cross-country team in high school simply because he was always fastest among friends escaping the police. But a marathon "just seemed outrageous, inhuman, and mysterious," he said. He had to try it.
Running has given him confidence to push himself and test himself professionally, and dive into uncomfortable situations.
The downside of 100,000 miles? His feet are so hobbled he can no longer wear dress shoes. "The funny thing is I so appreciate being able to run today, albeit much slower," he said. "I have frankly never enjoyed running as much as I do right here right now."
Many goals remain after today, such as "a speed trek to the top of Kilimanjaro."
Lypheng Kim, 17, a junior at Mastery Charter's Thomas Campus in South Philadelphia, will run his first marathon.
More than anything since he arrived from Cambodia at age 6, training for this marathon with a group, Students Run Philly Style, has made him feel as if he belongs here.
"It's more than just a team," he said of his fellow student runners and adult mentors. "It's more like a family. From the beginning, I felt really connected to everyone."
His parents speak little English, work in a factory. They don't understand how important running has become to him. He can't blame them. It is not in their culture and they work every weekend.
"Sometimes when I bring a medal home, they say: 'Oh congrats.' There's nothing more than that."
Students Run Philly Style pairs students with mentors and builds positive relationships through running. Lypheng could be the poster child. Since joining a year ago, he goes on runs with friends of every background. There is no pressure; they talk about everything. He tells them about years of being bullied or the academic pressure of junior year - he dreams of being a doctor.
Running friends took him out for his first-ever birthday party, bought him a cake.
He's also learned how to train, how to pace himself, and has improved. He ran his first half-marathon in September.
"Three miles before I finished, I almost burst out in tears it was so emotional," he said. "Coming in the top 10 with one of my teammates, it showed I could tackle something and succeed."
Brad Spicer, 37, of Salem, N.J., went to Elizabethtown College to play basketball. He never drank or took a pill. But when his basketball dream collapsed, he fell into depression, took a drink at a party, and became an alcoholic for nearly 20 years.
"Running saved my life," he says. "Addiction escalates to the point you can't stop. I did try to end my life because I couldn't stop."
In January 2011, he said, "I was arguing with my family. I ran out my front door, through a field, through a swamp, to get to a liquor store. I woke up several hours later. I took those same sneakers that I ran through the swamp in. I went for a run. I could only run for like five minutes. Every time I wanted a drink I went for a run. And I went for another run and another run.
"Last November I ran my first marathon in Philadelphia, which was really special. Since then I've run 10 more. Qualified for Boston. I've been on this incredible ride."
Spicer teaches middle school. He has a family. He was on the verge of losing everything, but now he's running to raise awareness about the dangers of addiction. And he has this incredible personal goal - to run 7,000 miles this year. That is roughly 20 miles every day for a year. Every mile he runs raises $1 for an organization that battles addiction. His website is www.run7000.net/.
"The real heroes are my wife and my mom," he says. "They're the ones who went through hell. They say I'm the original Forrest Gump. When I was 8, I had leg braces on."
Meredith Lambert, 29, from West Grove in Chester County, ran track and cross-country at Princeton and turned to marathons after that. She went to Temple law and works now for a Main Line firm, running before work with her sidekick, Bolt, an Australian-shepherd mix named after the world's fastest human.
Lambert hopes to be among the top women finishers. Her boyfriend and father will cheer her. She plans to run a relaxed race and enjoy the hometown course and crowd on a beautiful late-autumn day. To her, life can't get much sweeter.
Kerry Donegan, 31, a doctor in New York, is one of 1,400 runners welcomed into the Philadelphia Marathon after a storm-ravaged New York canceled its race two weeks ago.
A cardiologist, she runs because it sets an example for patients, clears her mind, and is a wonderful break from medicine. She will wear her New York Marathon shirt today but had printed on it, "Thank You Philly."
Brian Kline will run his 11th marathon, and fifth in Philadelphia, carrying an American flag.
"I first ran with the flag on the 10th anniversary of 9/11 to honor the victims and to show support for the troops," said Kline, a personal trainer who owns FitMix in Haddonfield. "It has the twin towers where the stars usually are, and says, 'We will always remember' across the stripes."
He's running to raise awareness for an organization, Team Red White and Blue, aimed at building a community of veterans and their families.
"I feel more comfortable with the flag in my left hand and only switch it to the right hand to give the left a little break," he says. "There is no technique except to raise the flag when someone beeps or spectators cheer. It's not heavy but definitely takes its toll as I add on the miles."
Read all of our coverage of this year's Philadelphia Marathon, including live race-day updates, at: www.philly.com/
Contact Michael Vitez
at 215-854-5639 or firstname.lastname@example.org. On Twitter @michaelvitez.