Before sunrise last Friday, Oz Pearlman loosened up in front of Engineers’ Gate, one of the entrances to Central Park. He rubbed up his thighs and underarms with petroleum jelly, then peeled off his toe socks and coated his feet. This would not be a typical weekday morning jaunt through Manhattan’s preferred and most storied running terrain.

Dressed in Ukraine’s national colors, and wearing two GPS watches to record distance and time, Pearlman laced up his Day-Glo sneakers and stood in the middle of East Drive, in front of a Ukrainian flag, with a handful of spectators. He planned to run all day and into the night as he attempted to break the record for most Central Park loops completed in a single day, while raising money to help Ukrainian children displaced by Russia’s invasion of the country.

Pearlman, 39, who lives in Brooklyn, is better known by his stage name, Oz the Mentalist. (Oz rhymes with “clothes.”) He finished third on Season 10 of “America’s Got Talent” in 2015, and has appeared on “Today,” “Live With Kelly and Ryan” and “Ellen.” His long run would be yet another display of mind over matter.

The record Pearlman hoped to break was set in 2021 by Robbie Balenger, an ultrarunner who rose to prominence by knocking off multiday ultradistance challenges. In 2019, Balenger ran across the continental United States. Last summer, he completed what he called the Colorado Crush: 1,176 miles of running and over 300,000 vertical feet of elevation gain in 63 days, capped off by the Leadville Trail 100-mile race.

According to Fastest Known Time, the digital platform that collects and certifies “F.K.T.s” on terrain both well known — such as the Seven Summits — and obscure, Pearlman would have to do more than simply run one mile longer than Balenger. He would need to complete another full loop.

Although the park itself was created in 1858, the first fastest known time in Central Park was set in 2020 by Aaron Zellhoefer, who ran 11 loops in just over 14 hours. It was one of thousands of F.K.T.s established during the pandemic when races were canceled and runners were looking for new challenges. Many of those records are regional and relatively inconsequential, but this one matters to many. Central Park is a global running destination and home to more than two dozen races each year. It’s where the New York City Marathon ends.

To prepare for the Central Park Loop Challenge, Pearlman completed several runs over 20 miles, usually on the road before or between shows. When he is home in Brooklyn, where he lives with his wife and three children, he literally runs errands, sweating through school drop-offs and pickups. He has trained in Central Park for nearly 20 years and committed every bend of the road, each hill and straightaway, to memory. “It’s home ground,” he said. “That six-mile loop is my comfort zone.”

But there would be a ticking clock. Central Park is open from 6 a.m. to 1 a.m., and runners are not permitted on the roads until five minutes after opening. They must be out of the park five minutes before closing time. That gave Pearlman 18 hours 50 minutes to set a record.

At 6:05 a.m. sharp, he took off hot. He ran uptown, counterclockwise, at a pace under 7:30 per mile. Mike Halovatch, a fixture in New York’s ultrarunning scene, was his only pacer for the first loop, which he finished in under 45 minutes. It would have been faster if not for last-minute advice from a stranger who insisted he walk the two big hills.

Pearlman has won the New Jersey Marathon four times and the Hamptons Marathon three times. His personal best in the marathon distance places him just outside the range of men invited to the Olympic trials.

“Oz is a true thoroughbred,” Halovatch said. Referring to Pearlman’s personal best time in the Philadelphia Marathon in 2014, he said, “You run a 2:23 marathon, that’s running.”

Pearlman wasn’t always fleet of foot. He was the lowest ranked runner on his cross-country team in high school, but by then he was already doing magic shows in restaurants. After a divorce left his parents in financial uncertainty, he said, he leaned into magic to put himself through the University of Michigan. After college, he was an entry level analyst for Merrill Lynch and moonlighted as a magician.

He worked restaurants on the Upper East Side, did bar mitzvahs and wowed colleagues at happy hour. His worlds collided during his investment banking career when he was hired to work an event in honor of a Merrill executive. When Pearlman turned a $1 bill into several Benjamins with a snap of his fingers, the boss was impressed, until he found out Pearlman worked for him.

“He said, ‘What the hell are you doing working here?’ And I thought, ‘What am I doing working here?’” Pearlman put in his notice a few weeks later, not long after running his first marathon.

He gradually shifted from standard magic to mentalism. “It’s a bit more cerebral,” he said. “It’s about trying to decipher and reverse engineer the way people think. Essentially, I’m trying to plant an idea in your head or get an impossible thought out of your head.”

He asked me to think of the name of my first crush, who happened to be someone I haven’t seen, heard from or even thought about in decades. He nailed it. While he was running. At Mile 80.

After finishing each loop on Friday, he took a question sent in from among his 812,000 Instagram followers. One asked, “Does running help your mentalism?”

“Mentalism helps my running,” he replied. “If I can get inside your brain, I can get inside my own brain when I’m suffering, dig deep and keep running.”

The sun broke through clouds on his third loop, and his pace held steady as the sky brightened and the miles piled up, much to the concern of Halovatch and his wife, Kate Pallardy, an elite distance runner and triathlete. They have learned from experience that a slower pace early usually yields a better result in this type of event. Pallardy ran 18 miles with Pearlman at midday, just five weeks after giving birth to her third child.

In total, about 40 runners came out to pace him. In typical New York fashion, many of them just happened upon Oz and joined right in. He chatted breezily, and did his best to entertain them all. “It’s the performer in me,” he said. But like Pallardy and Halovatch, he knew the suffering would begin at some point, and just before Mile 50, it hit hard.

“Your mind plays tricks on you,” he said as he finished his eighth loop. “You start thinking of how much further and how much time you have, and doubts creep in. They just eat at you. It’s your mind telling you to quit.”

Twenty miles later, on his 12th loop, his digestion faltered. He had been consuming nothing but gels (he sucked down two or three per lap), caffeine gummies and orange Gatorade. Perhaps that took its toll. Or it could have been that he had worked late the night before and managed only four hours of sleep.

He vomited twice and had to find a toilet. His pace dropped from eight minutes per mile to over 12. The color drained from his face. He felt blisters form on the bottom of his feet. His right shin started to throb. His team filled his hat with ice, which he dumped on his head to wake himself up. Once his stomach settled, he popped more caffeine gummies to keep himself humming.

As is often the case with ultra, that period of pain and deep exhaustion was chased by an extended flow state. Toward the end of his 13th lap, he hit top gear. Rocking to playlists he had curated for the occasion, he sang aloud as he ran. His 91st mile was his fastest: 6:43.

Pearlman completed his 16th loop, and 98 miles, at around 8:20 p.m., to equal Balenger’s distance record. He ran roughly four hours faster than Balenger. Two miles later, he hit 100 miles with a time of 14 hours 36 minutes, beating his own 100-mile record by two hours.

When he finished his 17th lap at 9:15 p.m. to set the Central Park Loop Challenge F.K.T., he paused to hug his wife and celebrate with friends who confirmed that he had also surpassed his fund-raising goal of over $100,000. But he wasn’t done. His pacers, some of them seasoned ultrarunners, wouldn’t let him go home. They insisted he tack on a few more laps to the new Central Park Loop Challenge F.K.T. So a few minutes later, he was running uptown once again.

On his 18th lap, he savored the slower pace and the hills because they allowed him to walk. It was obvious from his expression that his right shin was getting worse. He popped ibuprofen to keep the swelling down and the pain at bay, and kept moving.

His 19th and final loop was his victory lap. “I told the guys, we’re going to finish the way we started: strong. And I just went for it.”

He ran, all out, often with his eyes closed. It was up to his pacers to make sure he stayed on course, and they did. When he reached Engineers’ Gate for the final time just before midnight on Friday, after running a total of 19 loops and 116 miles, he fell to the ground, elated yet spent.

“I had a spectacular day,” he said. “There’s just no other way to describe it.”

Hilary Swift contributed reporting.