The 2018 Winter Olympics are well underway, and audiences around the world have seen a lot of wild science and technology outside of the actual competitions, including a norovirus outbreak, the blacker-than-black Olympic Plaza pavilion, the scandal surrounding sloppy Russian doping, and even live streaming VR coverage.

But it’s the tech that athletes are using — or forbidden to use — for competition that’s truly wild. Here are some of the most high-tech pieces of Olympic equipment athletes are rocking in Pyeongchang or had worn in training before they arrived. Most of it is actually illegal for competition.

Dutch Speed Skaters Trained with Haptic Suits

Dutch speed skater

Leading up to the Winter Games, star Dutch speed skaters Suzanne Schulting and Sjinkie Knegt trained in high-tech haptic suits. As the South China Morning Post reported, these suits constantly monitored their body positions, allowing coaches to recommend minor adjustments by vibrating different portions of the suits while the athletes were wearing them. With this kind of real-time feedback, these suits aren’t legal for competition, but the team hopes it’ll give them an edge. So far, the results are mixed: Schulting came in 30th in her first event, the women’s 500m individual race, but Knegt snagged the silver medal in the men’s 1,500m race.

U.S. Skiers Got Their Brains Zapped

In preparation for the games, U.S. skiers trained with headsets that administer transcranial stimulation — small, targeted currents of electricity — to the brain’s motor cortex. These headsets, produced by Halo Neuroscience, supposedly help increase the effectiveness of training. The idea is that electrically stimulating the motor cortex during training will make it easier for athletes to build new skills.

The U.S. ski team’s high performance director, Troy Taylor, told the BBC that the team’s Nordic combined skiers had seen the biggest gains in advance of the Olympics. “Jumpers experienced less wobble and applied more force in their jumps,” he said. The Halo headsets are also not being used in competition.

U.S. Skiers Used Strobe Glasses to Improve Focus

Vima REV

When athletes who are at the very top of their game compete against one another, every tiny bit of advantage counts. That’s why, as the BBC reports, U.S. skiers have been training with strobe glasses to strengthen their non-dominant eye. Just as most people have a dominant hand that they rely on more, most people also have a dominant eye. For skiers, the concern is that turns toward the non-dominant eye will be slower and weaker, and strobe training is meant to prevent that. These glasses made by Vima use a shutter to strobe the dominant eye, making the non-dominant eye get stronger.

“Taking information away in a strobe fashion wakes up the brain to take and use information it does see and process it faster and better,” the head coach of U.S. men’s alpine, Sasha Rearick, told the BBC. It’s still a little too early on in the games to tell whether the training worked.

Under Armour Debuted a New Speed Skating Suit

Under Armour designed the U.S. speed skating team’s uniforms for the 2014 Winter Olympics. These “Mach 39” racing suits were, to put it simply, a disaster. For the first time in 30 years, none of the U.S. skaters won any medals. What’s worse, some skaters and critics actually blamed the vented suits for being restrictive and distracting. U.S. Speedskating officials have since established that Under Armour is not to blame, but the whole episode was a public relations nightmare.

For 2018, the company hopes to redeem its image and bring U.S. skaters to the podium with a revamped suit. The new suit, according to Wired, is made from three different materials and is designed to reduce air resistance at key points on the body. One fabric called H1 is particularly rough, which helps create turbulence and prevent air from clinging to skaters and slowing them down. So far, it’s hard to say if it’s working, since about half of the events are finished, and no U.S. skaters have medalled.

Great Britain’s Skintight Skeleton Suits Are Barely Legal

In the skeleton event, riders rocket down an ice track at speeds approaching 80 miles per hour on a tiny sled, steering with their head and neck. At these speeds, aerodynamics become very important, but skeleton rules stipulate that riders’ suits must not have any added aerodynamic enhancement. This is meant to level the playing field since everyone has access to basically the same equipment.

But Great Britain’s practice runs raised concerns, as The Telegraph reports that the team is wearing suits with built-in ridges. These ridges, much like dimpled speed skating uniforms, can help create turbulence and reduce aerodynamic drag on the riders. Competitors spoke up when they noticed that Great Britain’s riders, who weren’t exactly ranked at the top of the field, started posting ridiculously fast times. The International Bobsleigh and Skeleton Federation weighed in, though, saying that since the ridges are built-in and not added on, they’re legal.

If you liked this article, check out this video: "The United States Ski Team Trains With Halo Neuroscience Brain Stimulation Gear"