Colin O'Brady calling his wife after reaching his goal of crossing Antarctica on the Ross Ice Shelf. (Colin O'Brady/AFP)

The week between Christmas and New Year’s Day is what one writer has called the “Sunday afternoon of the year,” a time for lazy reading and ambitious cooking projects — or, in Colin O’Brady’s case, the final, sleepless 80-mile leg of a two-month race across Antarctica.

On Wednesday, O’Brady became the first person to cross the continent solo, unsupported and unaided by wind power. He made the 932-mile crossing in 53 days, with only one half-day off to repair one of the skins that allowed his skis to grip the snow.

O’Brady’s accomplishment is the culmination of years of athletic feats.

The 33-year-old grew up in Portland, Ore. After graduating from Yale, he pursued a career in finance, but a freak accident on a trip to Thailand a few years later changed everything. On his trip, O’Brady was burned in a fire, suffering severe burns on the lower half of his body. His legs were so badly damaged that doctors warned he would never walk normally again.

Instead, O’Brady made a full recovery and, a just a few years later, won an Olympic-distance triathlon. Inspired, he quit his day job and became a professional triathlete, training for the Olympics. In 2014, he began his quest to complete the Explorers Grand Slam, a series of challenges that includes climbing the highest summit on each continent.

O’Brady prepared for his Antarctica crossing by putting in long hours at the gym. He did planks with his hands and feet plunged into ice water, then practiced undoing thick knots.

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Day 47: THIS TOO SHALL PASS. After having my best day of the expedition yesterday, I nearly had my worst day today. I went to battle hard with my personal demons today. My anxiety started building last night after listening to a huge wind storm grow outside. The rattling of my tent kept me up and I began to get more and more nervous knowing I had to go out in it. I did my usual morning routine and then stepped into the madness. As expected, it was brutal. Blowing snow, sub zero temps and zero visibility. I packed off and headed out into the whiteout. I just entered a part of the route known as “Sastrugui National Park” aptly named for having the biggest sastrugui on the route. Pretty much the worse place to find yourself not being able to see where you are going. Due to the massive sastrugi, it’s also the one stretch where no plane can land so you are in dire straights if an emergency occurs. That really started playing on my mind after I fell hard 5 times in the first hour. What if I broke a bone or a ski? Maybe I should stop? I bargained with myself and finally decided I had to set my tent back up, less than two hours into the day. I told myself in my tent if I wanted to keep going that I could put on my long skins for better grip on the uneven surface and then continue. But I knew the effort it would take to put up the tent in a storm, it’s unlikely I was going any further. I fought to get the tent up, got inside with my skis, skins and stove, and put on my long skins. It was now decision time. Go back out? The voice in my head told me to stop, wait out the storm, rest. But the other voice told me I needed to keep moving forward or I’ll run out of food. My mind was ripping me apart. I closed my eyes and decided to meditate for a couple minutes repeating my favorite mantra: “This too shall pass.” One way or another I’d find my way out of this. Calmed and with renewed resolve I got back outside, fought to get my tent down and packed and continued onward. The storm outside never got any better, in fact it got progressively worse. However I managed to calm the storm in my mind and knock out 21.5 miles today. A great day all things considered.

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Day 42: DREAMS INTO REALITY. Even though I’m 50 miles past the South Pole now, I can’t help but post one more image from the day I arrived - a dream come true. Plus, today is a very historic date. On December 14, 1911, this day exactly 107 years ago, Amundsen became the first person to reach the South Pole. Talk about inspiration. That was a true journey into the unknown that took years and years to complete. I finished a bike ride in 2016 and got the spark of inspiration for this project. I immediately came home and wrote it all down on my whiteboard. Since that day I’ve been working everyday to turn this dream into reality; training, fundraising, researching. The key is that each day I took a step toward making my dream a reality even with countless setbacks and mistakes made along the way, I kept trying. I haven’t realized the dream yet. That’s what I’m doing every day out here...taking step after step to make it come true. Whatever you are dreaming of in life, be that in business, art, music, love, entrepreneurship, sports - it can be anything. Stop just dreaming and take the first step. As in the immortal words of Walt Disney, “If you can dream it, you can do it!!” But dreaming alone won’t get you there. If it’s going to work, action is required. #TheImpossibleFirst #BePossible Shoutout to @samuel.a.harrison for snapping this amazing shot of me. Samuel and another scientist from the South Pole station read about my journey in the @nytimes and came outside to the Pole to cheer me on!

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After months of training, O’Brady flew on Halloween from Chile to Antarctica, where he began his trek.

O’Brady was on the move for about 12 hours most days, covering 20 to 30 miles each day. He dragged along a sled of gear that weighed 375 pounds at the start of the journey, containing a tent, cold-weather sleeping bags, solar panels, skis, a satellite phone, freeze-dried food and other items.

His final leg was particularly brutal — a 77-mile haul he completed in 32 hours. O’Brady stopped only once during that push to melt some ice, eat a double helping of dinner and call his wife to reassure her he wouldn’t do anything stupid.

“I don’t know, something overcame me,” he told the New York Times of his decision to press on. “I just felt locked in for the last 32 hours, like a deep flow state. I didn’t listen to any music. Just locked in, like I’m going until I’m done.”

O’Brady said the decision to complete what amounted to an ultramarathon in freezing temperatures after two months of constant physical strain came to him as he was making breakfast on Christmas morning. “I was like, all right, I have three more days left, how many hours is that of moving?” O’Brady told the Times. “People run 100 miles all the time.”

O’Brady’s accomplishment places him among some of the greats of polar exploration, including Ronald Amundsen, who led the first expedition to reach the South Pole, and Borge Ousland, the first man to cross Antarctica alone in 1997. (Unlike O’Brady, Ousland used a kite to help him travel.)

In finishing, O’Brady also narrowly defeated fellow adventurer Louis Rudd, 49, who was attempting the same crossing at the same time. At the finish line, O’Brady said he planned to pitch a tent, go to sleep, and wait for Rudd to arrive so they could travel back to South America together.

Even as he was rushing to finish, O’Brady said the final leg of his trip was emotional.

“I was reviewing the entirety of the expedition in my mind, and I was aware I’m going to tell this story for the rest of my life, but I told myself: you’re living this right now — live it!” he told the Times. "It was just getting deep with the senses. What does it sound like when your skis scrape against the snow? What does it taste like out here? Really just try and just live the experience.”

Read more:

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Six months, seven mountains, two poles — and the pursuit of one record