Joe McConaughy slaps hands with a group of through hikers who had been waiting to see him cross a bridge in Millinocket, Maine, in August after hearing of his attempt at breaking the fastest unsupported record for the Appalachian Trail. (Jessica Rinaldi/Globe Staff/The Boston Globe)

Joe McConaughy is the kind of person to whom things come easily. In 2014, after setting out on the Pacific Crest Trail for the first time, he broke the supported speed record. Supported, in hiking terms, means you have a team that meets you along the way with supplies. Eight months ago, when he started getting the urge to speed-hike the Appalachian Trail, "I really wanted to go for it," McConaughy said.

"I believe in myself a lot, and it definitely really humbled me and made me appreciative of the terrain," he said.

On Thursday, McConaughy beat the speed record for the Appalachian Trail by 10:41, finishing in 45 days 12 hours 15 minutes. Unlike the previous record holder, Karl Meltzer, he did it self-supported, with no crew following him and no prearranged support.

These types of speed record attempts began in 1948 and are becoming more common. To illustrate how fast this pace is, the average pace for a thru-hike of the entire Appalachian Trail is between five to seven months.

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When McConaughy started thinking about doing this, having already completed the PCT, he said, "I was a lot more knowledgeable this time. I know so much more about my body and what it takes, and nutrition and health."

"I have the ultrarunning background where I was running 100-mile weeks leading up to [it]. . . . I would try to do all my runs with the backpack on, so that my body got used to running with more weight. . . . I also did strength training . . . just to try to put my body through the hurt locker a little bit," McConaughy said.

When he started out on July 17, 2017, at 6:31 a.m. at Springer Mountain in Georgia, he carried a backpack that weighed seven pounds, plus water and food, which brought it up to about 25 pounds.

McConaughy ate 8,000 calories a day, including an entire sleeve of Oreos during lunch.

By Day 13, he was 685.6 miles in, going through Virginia, and by Day 22, he was halfway done with the 2,181-mile journey.

"If you told me halfway through on the trail how I did, I would be pretty disappointed, and honestly kind of surprised," McConaughy said. His intention in setting out had been to set a 43-day pace and beat the supported record by three to 2½ days.

"People might think I'm crazy," he said, "but I figured, I probably wouldn't do 43 days, and at the very least, it would give me some cushion on some days when I got injured, or something happened."

Like what happened on Day 28, when McConaughy got a small burn on his right foot that turned into a cut and then into an open sore.

"If I didn't have gauze, and I managed to bum some antibacterial foot cream off someone who wasn't using theirs. . . . I wouldn't have finished, I don't think," McConaughy said.

Instead, he kept going up through Connecticut, to Massachusetts, and then to Vermont.

"I always make fun of New Jersey, but going through New Jersey was actually one of my favorite states," McConaughy said. "You see parts of small town America which you would have never seen otherwise."

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By Day 36, he wrote on Instagram, "Tomorrow I am crossing into [New Hampshire] which is White Mountain territory."

The Whites are where McConaughy — a Boston-based runner and sales associate at EF College Break, a travel and education company — trained for the trek, in addition to spending two weeks in the Jasper National Park in Canada just before starting out.

"Thank God the whole AT isn't like [the Whites], because I wouldn't have broken the record," he said.

By Day 41, he wrote on Instagram, "Quick update, I got wrecked by the Whites. Blown up knees, quads, hammy, the works."

"I'll need to average 45 [miles per day] from here on out to break the record. . . . This section puts my hopes in jeopardy."

"Southern Maine is actually more elevation gain than the Whites and New Hampshire," McConaughy said. "It was so much more surprising and kicked my butt so bad."

By Day 43, he had 151.5 miles to go and under 70 hours to do it in to beat Meltzer's record.

Over the following 2½ days, McConaughy managed one day at 40.7 miles and then a 37-hour push to the finish, covering 110.8 miles in the longest stretch of running he had ever accomplished. He ended up at the top of Mount Katahdin, the Appalachian Trail finish line, at 6:38 p.m. on Aug. 31. It was raining, hailing, and the winds were 70 mph, but he had done it , and set a speed record in the process.

McConaughy's time has been verified by the Fastest Known Time board member Peter Bakwin, and GPS records shared with The Washington Post spoke to the validity of his attempt.

McConaughy later wrote on Instagram, "I honestly don't know what to say. I am in shock and pain, joyful and thankful, humbled and tired, in disbelief and exhilaration."

"I still haven't fully reflected on everything and internalized it, because I still haven't really slept since I finished," McConaughy said in an interview with The Post on Friday, less than 24 hours after finishing the trail.

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His girlfriend, Katie Kiracofe, and friend Josh Katzman had been waiting for him at the top of Mount Katahdin, along with his mother, and together they had camped out at the bottom of the mountain that night before driving back to Boston the following day.

"I'm really excited to get back, be in Boston, hang out with my girlfriend . . . and just take some time to assimilate myself back with the people I love," he said.

McConaughy is not planning any long-distance speed hikes for a while, though he does have his eye on some shorter trail speed records, such as the Long Trail in Vermont, the Wonderland Trail in Washington, and the Colorado Trail.

"When I think about it, and I ask myself, is someone going to break my record, or who is going to break my record, or what does it take to break my record, honestly there's a few days I think that you could take off what I've run," McConaughy said.

"I guess my small chip on my shoulder for something like this, and for future people attempting a record like this, is going with it self-supported isn't necessarily better or purer or anything like that, [but] it's more accessible. You don't need to be a headline sponsor athlete to go out and do something like that."