Why run a marathon? Pro-athletes and psychologists explain

Every year, there's a new story about someone crawling, being lifted, or not even making it to the finish line of a marathon.

And every year, as spectators watch in awe as thousands of athletes run a grueling, painful 26.2 miles in the TCS New York City Marathon, they may be asking themselves: Why do people choose to do this?

ABC News went to the professionals to ask why they put their bodies through this --if not for the grand prize and title at the end.

When asked "Why do people do this?," Tatyana McFadden, a five-time TCS New York City Marathon champion and 20-time Paralympic medalist, said she asks herself the same thing.

"When it's so tough, you're like, 'Oh, my God, why did I put my body through this?'" she said to ABC News. Many of the runners are running with a charity or fundraiser, she pointed out, meaning the connection to the race can be much deeper than a personal achievement. "It's very emotional ... Everyone is running for something, running for some cause."

Zackary Harris, the inaugural nonbinary division winner in the race's history, said they love the way it challenges their body and mind. They sometimes have to literally yell at themselves to keep their "feet up, head up" to make it through the race even when their body wants to stop.

"Running a marathon puts every single facet in your mind to its ultimate test, like, your body is pushed to its limits, your mind is pushed to its limit," Harris said to ABC News. "Throughout the course, you're having all these internal struggles with yourself. But then once you finally get to the finish line, it's like this sense of pure accomplishment that I don't think get happens in a lot of other athletic events."

Daniel Do Nascimento, an Olympian and Americas' marathon record-holder from Brazil, told ABC News that he never thought initially he'd be breaking records, let alone running for two hours directly.

"I thought I'd run for an hour, and then I did another hour ... and I felt so good," Do Nascimento said. That rhythm grew, until he ran with the best in the world and broke the Americas marathon record in 2022. It made him feel powerful, he told ABC News.

For Matt Llano, the first openly gay American professional runner, the sport is all about perseverance and community.

"You see just so many stories of triumph, and people who've gone through so many different things to get there on that day," Llano said to ABC News, describing the tearful, jubilant joy of people as they collapse crossing the finish line, or throw their hands up and cheer. "It just makes you think back on your own journey and what you have overcome to get to that starting line. Everybody has something, whether they think they do or not."

Llano said that the running community plays a key role in his love for the sport, and the growing inclusivity within it is a bright spot for him to connect with other athletes -- The NYC Marathon has been deemed a "safe space" for LGBTQ runners.

For non-professionals, who spend lots of time icing and massaging out their soreness before and after the marathon, the question of "why" may still be hanging in the air.

11-time-marathon-runner and State University of New York at New Paltz psychology professor Glenn Geher told ABC News that though the reasons for racing are different for everyone, there are some common threads that weave all marathon runners together.

Firstly, the "runner's high" is no myth as the hormonal aspect of marathon running plays a big role in why people feel compelled to join in. Running is known for giving athletes a rush of endorphins, and crossing the finish line of an hourslong race can be described by some as euphoric.

That feeling of pure achievement after months of training is undeniable and the hoards of spectators cheering certainly helps, Geher said.

"In reality, completing a marathon is not the impressive part (although it is the glorified part)," he said. Instead, he applauds the hours and hours of training that builds up into the final race day. "Effectively training for a marathon is really what's impressive -- and that end of things often goes unseen."

Geher added that completing a marathon is also a way to socially signal one's traits on dedication, discipline and time management -- all required for getting through a successful race.

"I work with a lot of people in different contexts and different groups. You want people who are diligent, you want people who are hardworking, you want people who are gonna ... 'go the extra mile.' Marathon finishers fit all those details in a very profound way," Geher said.

Runners may also be inclined to run a marathon because, evolutionarily, walking or running long distances is in our blood, Geher said.

"Everyone was [nomadic,] and while nomads don't run marathons, it is not uncommon for a nomadic group to travel as far as 20 miles in a day," Geher, who specialized in evolutionary psychology, said. "Especially when [humans were] hunters, they weren't faster than a lot of the game that they were chasing ,right? They had more endurance. So it does seem like to some extent long distance running, maybe not marathon running per se, but long distance running does seem to have a long history in the human evolutionary experience."