A Massachusetts woman has become the first American woman to ski solo and unsupported to the South Pole.

Monet Izabeth traveled 700 miles over 57 days, pulling a 250-pound sled the entire time. She has returned to Massachusetts, and joined GBH Morning Edition Host Mark Herz to discuss her journey. What follows is a lightly edited transcript.

Mark Herz: First, what is your background athletically and how did you train for this?

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Monet Izabeth: Well, I have to say, I am not a professional athlete. Just point blank right out the gate. My dad used to say that my favorite sport was the one where I didn’t sweat, because I never really was into sports that much. But I started getting into hiking and just pushing myself more and more when I was in my 20s.

So I’ve been training for almost three years at this point, and I’ve been training physically for over two years. I had been training five to six days a week — and that included pulling tires, which is one of the best ways to mimic pulling a sled. So that’s like a fully stocked fridge is how I like to compare it to, so people can understand it was very heavy and a lot of weight. So to prepare my body for that, I literally used the same harness that I used on expeditions to pull two tires wherever I was in the world at the time. So on the beach, on the road, on trails. And then I also would do strength training, cardio, lots of stretching. And then, I also had to prepare mentally, which one of the best ways to do that was to just get expedition experience. So I did a 30 day crossing of the Greenland Ice Cap. And then also did two solo expeditions in Minnesota and Norway.

Herz: Now, 700 miles over 57 days. How did you lay that out? What is the math on that?

Izabeth: The math is about 12 miles a day, which probably doesn’t sound like that much. In the beginning, I went a lot slower. On my slowest day, I think I did four nautical miles, which is about six statute miles. That’s pretty slow when you’re skiing 11 hours to only do six. But towards the end, when I was really pushing hard to try to finish as soon as possible, I had to hit about 16 miles a day for the last four days. That was my goal. So I was skiing 12, 15 hours a day to make that happen.

Herz: What about all the safety considerations on this?

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Izabeth: There’s a company, Antarctic Logistics and Expeditions, and they kind of have a monopoly on private expeditions in Antarctica. So if you want to do a private expedition, you have to sort of qualify through them. They make sure that you’re ready, and they were really involved in making sure that my training was appropriate. And then they’re in charge of my logistics and safety. So I had a safety call with them at the same time every single day. It was at 7:50 p.m. I would call them, they were the only people that I spoke to over the phone on the expedition. It was about five minutes a day that I would have human contact like that. I would tell them where my location was, how far I traveled. They would make sure that I wasn’t going absolutely insane, that I was sort of like, 'oh yeah, I’m doing great. The dinosaur outside my tent is fed.’ And then if something had gone wrong, or if I had missed a call, that would have triggered an emergency response.

Herz: And the mental challenge of this and the lack of contact with people — talk about that.

Izabeth: Probably because I’m an introvert, being alone was very easy. That wasn’t difficult at all for me. Honestly, I was so busy on the expedition. There’s no downtime. That for me is really mentally a hard part. You’re either skiing, eating or sleeping. There’s not time for anything else and you’re always rushing to the next thing and thinking about the next that you have to do. So when I’m eating, I’m thinking about how fast can I finish this meal so that I can sleep for as many hours as possible. But mentally, there were a lot of other things that were really difficult.

I didn’t really realize how the mental pressure of the mileage that I needed to achieve would really weigh on me. You know, my longest solo had been two weeks and I was able to sort of focus more on routines than trying to get mileage. The extreme pressure of 'you have a very long expedition ahead of you and you know that every mile counts’ and you’re trying to balance, well, 'is it sustainable if I ski 10 hours a day, or 11 hours, or 12 hours’ and at the end, your body has been pushing so hard. You’re so tired every single day. Every single day is really, really difficult. You have days that are not as difficult, but every day is hard. And you’re exhausted by the end of every single day and you know I would have a really, really hard day on day 20, and I knew I have at least 30 hard days ahead of me. And the mental fortitude needed to be like, 'I can’t focus on the 30 days number, it’s just too big. I just have to focus on, I’m just going to eat dinner and then I’m going to go to sleep. And that’s all I’m thinking about.’ And in the morning, I would always feel better and [be] ready to attempt it again. And then it’s just about, I just gonna focus on [having] one foot in front of the other today. That’s all have to do. And then you do it again the next day.

Herz: Were you listening to music or podcasts?

Izabeth: Not podcasts. I’ve never really been a podcast person, but I did listen to music and I listened to a lot of audiobooks. Some of them I listened to twice. On day 31, I unexpectedly lost access to 98% of my music. So I was left with five albums, which was, I mean, I felt like I got lucky. I had Lorde, Pure Heroine, I had Taylor Swift, Reputation, and I had two Adele albums. So it was like strong women. There were days where I just listened to Reputation on repeat for three days in a row.

Herz: What did it feel like when you finally reached the South Pole?

Izabeth: It was overwhelming. I wouldn’t let myself believe the expedition was over until I could see the pole because I woke up on the last day to a whiteout, which is one of the mentally hardest days that you can have because all day they call it 'skiing inside of a ping pong ball.’ All day you cannot see any definition, anything. And so on that last day, when it was a white out, I was like, okay, Antarctica is not letting me go easy up until the last day. I wouldn’t let myself believe that, OK, today is definitely my last day, because it could have ended up not being my last day if I was moving a lot slower than I thought. And I couldn’t let my body sort of release or relax into thinking that.

About halfway through the day, the clouds cleared a little bit and I saw buildings on the horizon and I hadn’t seen a building in months. And I knew that was the South Pole. And then the clouds came back in, I couldn’t see a thing for the next six hours. So for six hours I was skiing blind. I knew I was going to get there eventually. So when I finally reached like within the depths of the South Pole, which really kind of looks like a construction site, it doesn’t really look like what you might think it looks like. There is a ceremonial pole with flags around it but it’s right outside the American research base, which looks like a fortress. So after like no sign of humanity for 57 days it’s suddenly overwhelming signs of humanity and it’s not very pretty. It was the ugliest part of the expedition I would say.

But actually reaching the South Pole and just knowing that once I stopped at that pole, I could unclip my harness for the last time and I would never have to pull those sleds again if I didn’t want to — it was overwhelming. I screamed, I let out some sort of primal, guttural scream when I was there. And then it’s just all of a sudden it’s over. I’m sitting in a chair for the first time in 57 days. You know, there’s a chef at the camp at the South Pole, so I had a meal cooked for me. I was drinking water out of a glass that I didn’t have to melt myself, and it was hard to believe that it was suddenly over.