There are mountains in the Alps, from Austria to France, that veteran alpine racers have skied dozens of times over the years, so often they know every curve and can anticipate every bump.
"There's some guys on tour for 15 years who have 60 runs down these hills," said American skier Travis Ganong. "At that point, it's kind of ingrained — they know where to expend energy, where to save energy, where to push the line and where to hold back."
And then there's the downhill course for next month's Pyeongchang Games, located in the Taebaek mountains about 90 miles east of Seoul, far removed from the World Cup circuit and foreign to most ski racers. Most of the world's top skiers have raced the Olympic course only a couple of times.
Looking for an edge, the U.S. alpine team turned to virtual reality technology that allows American racers to memorize the hill and take hundreds of virtual runs down a fast, tricky course. Instead of getting a single training run in the days before the Olympic competition, many of the U.S. racers will step into their skis having spent several months virtually racing the course with the aid of a 360-degree video and a headset.
"If we can enhance their ability to learn that course, you'd certainly think that would have a positive benefit on them," said Troy Taylor, the high performance director for U.S. Ski and Snowboard Association.
Entering race day, he estimated, the average World Cup skier will have been on the Jeongseon course fewer than a half-dozen times. By comparison, he said the U.S. team can easily squeeze in dozens of virtual runs in a couple of days, ensuring every skier is as prepared as possible for a run they've spent four years dreaming about.
The U.S. skiers are the first known Olympic team in the world to utilize virtual reality in their training. In the United States, many professional and college teams use the technology, though the point-of-view is usually stationary and not flying down a mountain at 80 miles per hour.
Two years ago, Taylor connected with STRIVR Labs, a Palo Alto, Calif.-based company that's considered a leader in the field for sports teams, and presented the problem. The skiers would be facing an unfamiliar mountain, but they had a small window of opportunity. There was a World Cup stop in 2016 on the Jeongseon course and Taylor hoped STRIVR could capture video during that visit that would be helpful in Olympic preparations.
STRIVR works with a variety of sports outfits, but the company had never tried anything like a downhill course.
They attached a 360-degree camera to the helmet of one of the coaches and sent him down the course dozens of times, trying to find the same line that racers would ski two years later in the Pyeongchang Games. STRIVR then stitched together the video and sped up the footage to match the speed of the fastest racers.
Derek Belch, the company's CEO, knew the challenges from the starting gate. Virtual reality that features motion often results in nausea for the user. Virtually weaving your down a steep hill at speeds reserved for interstate highways felt like a certain stomach-turner.
STRIVR tried to stabilize the video and ski team officials paired the headset with other movements to keep the athlete moving with video.
"It actually ended up better than I thought it would be," Belch said. "... It's all about what the stomach can endure. I think one thing we actually underestimated was how solid the stomachs of these athletes are."
Most of the ski team has tried it but while some have utilized virtual reality dozens of times, others didn't feel as comfortable.
"You watch it and you get pretty sick and dizzy," said Ganong, who tore his anterior cruciate ligament earlier this month and will miss Pyeongchang.
Resi Stiegler, who's entering her fourth Olympics, specializes in technical events and says it might be more beneficial for downhillers. She's tried it several times but always falls victim to motion sickness.
"I think the speed girls can really, really benefit from it," she said. "And younger girls who haven't skied the course before, they can learn what to expect before they get there."
Officials were encouraged by the feedback and expanded their use of the technology beyond the Olympic mountain. They now travel with a 360-degree camera and have built up a library of World Cup courses that allows skiers to train for a race in Switzerland, for example, from a hotel room in Spain.
And they've especially found that it can be a valuable tool for injured athletes. The virtual runs allow those who can't physically get on the mountain to mentally practice racing any of the dozens of courses the U.S. ski team has recorded.
At the USSA's Center of Excellence in Park City, the team also utilizes a giant simulator housed in the organization's gym. A skier steps into bindings and faces a huge screen that displays a course either via video or computer-generated imagery. As the racer appears to move down the course, the simulator whirs to life, creating movement and generating forces that mimic the sensation of skiing. Steven Nyman, who missed most of the past year with a torn anterior cruciate ligament and is hoping to make his fourth Olympic team, said the simulator is a good bridge to returning to the mountain.
"When it comes to downhill, there's nothing like it obviously. But when you're making slalom turns on the thing, it's fairly realistic," he said. "It gains a lot of energy, there's a lot of pressure and rebound and that's what I was trying to do: Load up my left knee and see how it would react. Once things were feeling comfortable, I was like, 'Oh cool, I think I'm ready to go on the snow.'"
Skiers, both injured or healthy, can pair the simulator with footage of the Pyeongchang course or even strap on the virtual reality headset. Ted Ligety, a two-time Olympic gold medalist who's overcome a series of injuries in recent years to qualify for his fourth Winter Games, said it can help skiers identify landmarks and memorize changes in the terrain.
"It's still a far cry away from the actual sport," he said. "It's cool on the visual side of things. ... Especially on the downhill and super-G side of things, you can see the hill. That can be important in those events."
Most of the U.S. ski team has used the virtual reality headset or the simulator at least once, and Taylor said some have been using it at least weekly since the summer. While they've been focused largely on their World Cup season, he said, many will start studying the Pyeongchang course in more earnest in the next few weeks.
While virtual reality might be making its debut as a training tool at these Olympics, the technology is relatively new and many think it'll have an even bigger impact four years from now. Scott Reiwald, the USOC's high performance director, said he could see virtual reality being used in the next Olympic cycle to prepare athletes in the biathlon and some of the sliding sports, too.
"We've got our feet in the water. ... We're looking for opportunities and ways to expand that," he said. "It's happening but not as systematically as we'll hopefully be using it in four years time."
STRIVR's Belch notes, though, that there are limitations posed by most winter sports, such as snowboarding or figure skating. "I don't want to do anything goofy. ... I think there's only a handful of opportunities that are truly doable to be legit in VR," he said.
"In the case of what we're doing for the ski team, it's really a phenomenal use case. They will set a course a certain way for the Olympics and if they're not prepared for it - for those fractions of a second they can shave by knowing where the gates are going to be and having a comfort level of what that mountain looks like - you're at a huge disadvantage. This is something that we thought was a no-brainer use case as far as creating a competitive advantage."