How an Ultra-Endurance Athlete Is "Bulletproofing" Her Body to Break a Record in Antarctica

Updated on 11/12/2019 at 10:10 AM

Hamish Frost

Jenny Davis can tell you, in close-up and vivid detail, what it takes to ski through a snowstorm in Antarctica. There's the unimaginable cold (somewhere around minus 40 degrees Fahrenheit), the thick layers of snow dragging at her skis and sled, the locked-up pain in her neck from staring down at her compass, trying to stay on course. But set all of that aside for a moment. The real issue was the whiteout.

"You cannot see up. You cannot see down. You cannot see a horizon," Jenny remembered. "It's like being inside a marshmallow. That's the only way I can describe it." Totally disoriented, her nausea became so intense that she threw up into her face mask, where the vomit froze immediately. The storm was so unrelenting and the air so cold that she couldn't afford to stop and clear it out. "I spent the rest of the day skiing with chunks of frozen vomit inside my mask," Jenny said. By the time she collapsed into her tent hours later, "I was just a broken human being."

This is what it takes to make a run at an unassisted, unsupported, ultra-endurance speed record in Antarctica: a cross-country skiing expedition of over 715 miles to the South Pole, in less than 38 days, 23 hours, and five minutes. Jenny's attempt on it in 2018 was beset by a series of snowstorms, unusually heavy snowfall, and eventually a bowel infection that forced her to call for a medical evacuation with two weeks to go. She left Antarctica heartbroken but knew almost immediately: "I am not done with Antarctica. I'm coming back." At the end of 2019, she's going for round two.

The Making of an Ultramarathoner

The race that started all of this was half a world away from Antarctica and its marshmallow snowstorms, on a small island in Northern Scotland. Jenny, who is British, was there on vacation when she caught wind of a race the next day, something called an ultramarathon. "It was a lap of the entire island, this tiny, beautiful island. And I was looking at my friends like, 'Guys . . . we should enter that race tomorrow,'" she remembered. "And they're like, 'You're crazy. It's 35 miles.'"

Crazy, but committed. With no training and only one marathon under her belt, Jenny did the race and fell in love. "This is so civilized," she remembered thinking. "You run for a very long time. You talk while you're running. You chat to people. There's cake."

Pain is an element of doing ultramarathons. To qualify for the name, the race must be longer than 26.2 miles, or a full marathon; pain is part of the deal. "But you really quickly forget about that," Jenny said. As her career took off and she made the transition into a professional athlete, Jenny became obsessed with finding her physical and mental limitations. Without injury or illness, she wondered, "What event or expedition could I do where I pulled the plug? Where I say, 'I actually cannot take another step?'" She wanted to travel to the edge of endurance.

Training For a 715-Mile Race

There's a key caveat to the Antarctica speed record: it has to be done unsupported and unassisted. That means no outside help, no plane delivering more food or supplies, no truck or motorbike or means of transportation that isn't human-powered. Jenny had to be in good enough shape to ski the entire distance, 12 to 14 hours a day for 38 days. And she had to get strong enough to do it while dragging a 180-pound sled of food and supplies, uphill and into the wind the whole way.

Jenny's first attempt required two years of preparation, and recovering from it took several months. Once Summer 2019 rolled around, it was full throttle on the training for attempt number two. Her mind-boggling training regimen requires six workouts a week: three weightlifting sessions and three long conditioning workouts, walking for seven or eight hours on a treadmill set to maximum incline. To mimic the drag of the sled, she straps herself into a bungee cord harness and attaches it to a 220-pound weight behind her. To acclimate to Antarctica's high elevation, much of her training is done in a high-altitude gym; now, just weeks away from her second attempt, she's even sleeping in a high-altitude tent. Between the physical training and the mental (visualization and meditation), Jenny said, "you basically need to bulletproof your body as much as you can."

For fuel, Jenny (amazingly) has used the low-carb Atkins diet for years. "I'm a low-carb athlete," she said. "That's how I perform much better." For what she does, it makes sense. Jenny estimated that she burns about 10,000 calories a day in Antarctica, but she's limited to packing about half of that. Whatever she brings has to be as fuel-efficient as possible, and fat and protein are more calorie-dense than carbs.

The Final Preparations

Just weeks away from her second attempt (Jenny will leave the UK in mid-November), the memories from last year feel more vivid than ever. There was the surreal moment of getting off the plane in Antarctica, turning to watch it fly away, and realizing how alone she truly was. There were the good days of skiing, when hours flew by and she moved through a calm, purposeful "flow state" that felt like meditation.

And there were the storms, the cold and disorientation that proved the biggest test of resilience. After skiing herself into exhaustion on the day of the marshmallow-like whiteout, Jenny collapsed in her tent and reached for her radio. She was required to update Antarctica base camp on her location.

"Oh, so you skied today," the operator said.

"What do you mean, I skied today?" Jenny responded. He told her everyone else in Antarctica that day — tourists looking for penguins or visiting the South Pole, even an athlete racing for the men's speed record — had stayed in their tents. Jenny was the only one who'd faced the storm. "No one told me I could stay in my tent today," Jenny thought. "What the hell?" Then it started to sink in: all the guys had stayed in their tents, and Jenny had skied. "Yeah," she remembered thinking. "I'm a badass."