How an Extreme Endurance Athlete Trains to Trek 704 Miles From Antarctica to the South Pole

Jenny Davis likes to run and ski long distances. Really long distances. In December, the 32-year-old extreme endurance athlete will attempt her longest distance yet: a 704-mile trek from Antarctica to the South Pole.

“It’s something I’ve been building up to for the past two years,” Davis tells SELF of the attempt, which will be solo, unsupported, and unassisted. That means the London-based pro athlete will be traveling alone across the arctic tundra—primarily on skis, though there may be portions where she runs—and must pull with her everything she’ll need during the multi-week journey: Clothing, food, water, a tent, sleeping bag, backup gear, first aid supplies, and more. In total, the pack, which will be affixed to a sled, will weigh more than 170 pounds. If Davis completes the journey in less than 38 days, 23 hours, and five minutes, she’ll break a Guinness World Record.

Less than two months out from her planned start date—Davis hopes to begin trekking on December 5th or 6th, weather dependent—she is “ready to go.” The Scottish-born adventurer, who works full-time as a lawyer, was inspired to take on this challenge after reading books about female arctic explorers and successfully finishing several long distance races and training sessions in the arctic elements. “It’s a lot of fun,” she says. “There’s some insatiable interest within me to explore. To not only physically explore, but mentally explore where my own capabilities lie.” If completed, her trek to the South Pole will be her longest journey yet, and by far the most brutal.

According to the Guinness World Record webpage, the pole sits at an altitude of 9,301 feet, and Davis’s entire journey to get there from the starting point at Hercules Inlet in Antarctica, where she’ll be dropped off via airplane, will be uphill. What’s more, the atmospheric pressure in that part of the world makes it feel more like 11,000 feet above sea level.

“It will be a shock to the system,” says Davis. “When the plane drops me off, waves me off, and goes ‘bye!,’ I will either burst out laughing or burst into tears.”

Once she begins the journey, Davis says she’ll take each day as it comes. “I would love to have a specific plan [in terms of miles completed per day], but what I’ve learned from all other expeditions in the arctic is that it can be demoralizing if you set a specific goal,” she says.

Instead, she’s focused on preparing herself as much as possible beforehand—both physically and mentally—for the unknown that lies ahead. Here’s a look at what that involves.

Davis’s training involves a mix of weight lifting, bootcamp classes, high-altitude cardio sessions, and eight-hour (!) tire pulling sessions.

To prepare her body for the grueling cardio and strength challenges that await, Davis, a long distance runner, has embraced heavy weightlifting. This involves four sessions a week in the weight room doing a variety of movements, including heavy deadlifts, snatches, and other exercises to build up strength and power in her hip flexors. She also attends Barry’s Bootcamp four times a week.

But that alone isn’t enough to prepare Davis for the difficult task of pulling her 170-plus pound pack for days on end, and so every Saturday and Sunday, she straps on a weighted vest, laces up her hiking boots, and spends eight hours each day dragging tires—two or three large, heavy ones—along sand, mud, dirt, and grass paths in the countryside of London. “I get a lot of funny looks,” says Davis. “I’m running out of friends who will come with me because they find it boring. Even my dog won’t come with me anymore.”

On top of all that, to prep herself for the high altitude she’ll encounter in the arctic, Davis spends about four hours a week rowing, running, and cycling in a high-altitude chamber, a tent-like contraption that simulates the effects of high altitude on the human body. About a month before the journey, she’ll begin sleeping in a high altitude chamber every night to further acclimatize.

Nutrition is another key component of her prep.

Davis estimates she’ll burn about 10,000 calories per day while completing the challenge, yet her pack can only hold enough food to cover 5,200 calories per day. That’s why she’s been trying to gain weight in advance of the trip.

On a long training day, her typical breakfast involves eggs, avocado, and smoked salmon, and the rest of the day, she’ll subsist on Atkins protein bars, chocolate shakes, trail mix, and chocolate peanut butter cups (Davis is a paid spokesperson for the low-carb brand), as well as dehydrated meals, like pad thai and curry dishes.

Davis’s nutrition plan during the trip itself will remain fairly similar, though the egg and salmon breakfasts will be subbed with granola and coconut milk. “I try to keep it fairly consistent,” Davis says of her eating. “At this point, I know what works well for me and what my body can tolerate.”

Perhaps most important, though, is the mental training, which involves becoming “comfortable with being uncomfortable.”

Though it will be summer in Antarctica when Davis begins her trek, the conditions will be far from balmy. The highest temperature ever recorded at the South Pole was 9.9 degrees F, and weather during Davis’s attempt will likely be consistently below 0 degrees F.

“The wind is what really gets you,” says Davis, who will protect herself from the elements with a midweight base layer, plus a windproof outer shell, and a down skirt. She’ll also ensure her hands and face are completely covered at all times.

Yet clothing can only do so much. To prepare herself for the mental challenge of pushing through severe physical discomfort, Davis has been regularly jumping into cold ice baths or chilly rivers midway through training sessions. She also occasionally limits her water supply so that she can learn how to function while dehydrated.

She’s also been prepping with “a lot of visualization,” particularly about the moment when she will be dropped off and find herself completely and utterly alone.

For safety’s sake, Davis will carry a special satellite phone that will allow her to communicate with the outside world during the journey. Her main point of contact will be her dad, who is serving as her “expedition manager.” They’ll check in with each other every day, and he’ll provide her with weather reports for up to three days in advance. Davis will also speak with a logistics team every night for 10 minutes, which includes a doctor who will ask a series of questions evaluating her health. Plus, Davis will carry a live tracker. Should anything go wrong, help can be fly in in a matter of an hour or two.

“I’ll see what’s going to happen out there,” says Davis. “I’ll be alone over Christmas and New Year’s. There are definitely going to be tough days.” Aside from the solitude, her biggest concern is bad weather.

She describes “white out days” that she’s encountered during previous trips to the arctic where the wind blows so intensely that “you can’t even see your hands in front of you,” says Davis. “The only way I can describe it that it’s like being inside a marshmallow.” During these types of days, which she anticipates may be come during this trip, Davis will simply stare at her compass and stay positive with the help of music, audiobooks, and audio messages from family and friends.

“I’ll put on the Spice Girls and tell myself, Ok, here we go.”