So he jumped into the frozen lake wearing nothing but a swimsuit – did the backstroke, dove down 70 feet, and generally alarmed onlookers. Severinsen found this swim "fun" enough that he decided to do it again, a year later, when he challenged a decade-old ice-swimming record set by Wim Hof of the Netherlands, who, in March 2000, near the Finnish village of Kolari, swam 190 feet under the ice of a frozen lake. Severinsen had seen that feat on YouTube and wasn't impressed.
"He almost passed out," Severinsen said. "They had to drag him out of the water."
Severinsen, who has a Ph.D. in medicine and a master's in biology, doesn't earn his living from ice diving. But his cold-water exploits do bring attention to his other work: teaching highly paid, highly competitive corporate executives (and athletes, including champion cyclist Alberto Contador) who are looking for an edge, about the art and science of breathing. These lessons, at what he calls his Breatheology Academy, are not held in the frigid climes in which Severinsen often competes, but typically in a more relaxed, tropical location. There's good food, motivating and counterlogical conversation of the TED Talk variety, as well as swimming, meditation, and lectures on the benefits of better air intake. Severinsen contends that optimal breathing, with its focus on physical, mental, and emotional self-awareness, can be an effective weapon in the world of corporate warfare. Troels Hviid, a 37-year-old Microsoft project manager from Denmark, attended a weeklong seminar held on a boat in the Red Sea off Egypt. He uses the techniques he learned there doing deep dives to stay calm in pressured work situations. "You take a big breath and go down," he explained, "but the panic quickly grabs you, and I had to work on the mental side to stay calm. You have to generate a lot of positive thoughts to preserve oxygen." For this, and other instruction, Severinsen charges as much as $10,000 per week, per person, with recent sessions taking place in Las Vegas and San Diego.
Severinsen made his attempt on Hof's record in March 2010, in Denmark's Lake Knudsoe, 20 minutes from his home in Aarhus. His training for the feat included swims in the North Sea, which, because of the salt content, drops below freezing. Hundreds of Danes turned out, despite the cold, to witness Severinsen, in his now-signature Speedo, clip into a safety line, work through his breathing routine, and then slide into a square black hole in the frozen lake and swim beneath the ice until he'd reached another hole 236 feet away. The air was 2 degrees Fahrenheit. The water: 38. Severinsen spent 96 seconds in the water, and unlike Hof, he came out with no assistance.
Afterward, Severinsen, instead of warming up, took a victory lap on the ice, waving his towel behind him and playing to the crowd. Later, he would admit that the swim had been more difficult than he'd let on. "I'm not a crybaby, but it was very unpleasant and very noticeable," he said. "I'd never felt this kind of core cold." When asked how he beat Hof's record so easily, he said, "I'm not different from any other person. I just have the ability to shut down the sensory register for pain and discomfort."