The freestyle skier and X Games gold medalist Tanner Hall is one of the first active professional athletes to formally partner with a cannabis company. Photograph by Aurora Photos / Alamy

In February, Tanner Hall, one of the greatest freestyle skiers of all time—he won seven X Games gold medals and four silver in the Big Air, SlopeStyle, and Superpipe events between 2001 and 2009—signed a deal with a Denver-based cannabis-accessories company called Black Rock Originals. Hall, who is now thirty-two and based in northern California, near Lake Tahoe, helped the company create the Skiboss Collection, which consists of rolling papers, a cheese-grater-like card for grinding nuggets on the go, and a lighter, all tucked inside a travel-friendly pouch.

“We were all stoked,” Hall said recently, referring to everyone’s satisfaction with the finished product. He’d just returned to California after a few weeks of “ripping” in British Columbia’s Selkirk Mountains. Near a backcountry lodge he co-owns, Hall and twelve pals built what he described as “a twenty-two-foot-tall Hot Wheels-type loop out of wood.” He continued, “We all filled it in and skied around Evel Knievel style. We crushed it hard.” The entire effort was filmed for a ski movie planned for release on iTunes this fall.

Hall is the first skier and, it appears, the second active professional athlete—behind ultra-runner Avery Collins, who is sponsored by Mary’s Medicinals—to formally partner with a cannabis company. For those who know him, this is not a big surprise: Hall has also inspired a line of ski gear (including a backpack and high-performance mittens) with the company DaKine, known, winkingly, as THC—that is, the Tanner Hall Collection. Still, it was an unprecedented move for a skier, even in the latter stages of his career, to accept outright sponsorship from a weed brand.

Black Rock Originals, for its part, presents itself as the anti-stoner cannabis company. It promotes a series of online videos showing active and athletic people using cannabis with the hashtag #IAmNotLazy. One of its informational films is called “How to Exercise High.” The company even has a testimonial from a retired gold-medalist snowboarder about the useful effects of cannabis in sport. Ross Rebagliati won the giant-slalom event at the 1998 Winter Olympics, in Nagano, Japan, with THC, pot’s main psychoactive molecule, in his blood. (The gold medal was revoked on account of a positive drug test, then restored on appeal, because marijuana was not on the banned-substance list.)

Hall, too, believes that using cannabis can be beneficial to athletic performance. The proof, he says, is in his trophy case: he was on “chron,” as he prefers to call cannabis, when he won each of his medals. “I used it when I competed at the X Games,” he told me. “It helps with the stress, with the anxiety. And then, afterwards, as a relaxing agent and pain reliever. When your body is all tensed up, if you’ve got a pinched nerve or something, chron helps with that. I wouldn’t think about not using when I ski, because I don’t really know anything else. I’ve used it on a daily basis for about half my life, since I was maybe eighteen or nineteen. I prefer joints, but I also like edibles and vaporizers.”

He continued, “If you’ve ever skied on a powder day, you know you’re gonna stop in the trees at least two or three times a day to smoke a joint because of how good the snow is and how good a day it is. It brings you and your friends together. You give thanks to the mountain and the day and have a little meditation and just keep on ripping. It’s been a part of skiing for a long time.”

It’s long been a part of other sports as well. In late February, Ricky Williams, the 2002 N.F.L. rushing leader, was introduced at the Southwest Cannabis Conference and Expo, held in Fort Worth, Texas, as “the father of cannabis in sports.” He reportedly told those gathered, “I think if we open our minds and are willing to put our necks out there and be ourselves, we’ll prove to ourselves we’re O.K., and we’ll prove how wonderful this plant is.” According to the Denver Post, a 2013 survey found that seventy per cent of N.F.L. prospects used marijuana in college. Just this week, the Baltimore Ravens’ offensive tackle Eugene Monroe donated ten thousand dollars to a marijuana-research group, exhorting other players to follow suit, on Twitter: “Let’s put our hard earned money towards our health and wellness futures.”

At last month’s Cannabis Collaborative Conference, in Portland, Cliff Robinson was the keynote speaker. The former N.B.A. All-Star—who was suspended by the league multiple times for violating its drug policy decades ago—is starting an Oregon grow operation called “Uncle Spliffy.” He recently told the Portland Business Journal that he wanted to dispel “the stigma around cannabis, the misperception that athletes and cannabis are incompatible.”

The idea of cannabis shared by Hall, Robinson, and others seems almost comically at odds with the more common take on the drug as a stagnating, stultifying, couch-gravitating force. But their view is partly reinforced by the policies of the World Anti-Doping Agency, which prohibits the use of the plant in competition for meeting all three of its disqualifying factors: it violates the “spirit of sport” (because it is still illegal in many places), it’s deemed a “health risk” (“decreased cognitive performance” is cited), and it can “enhance performance”—it simultaneously reduces anxiety levels and increases the flow of air to the lungs. (Cannabis is a bronchodilator that has been studied as a treatment for asthmatics.)

“A lot of athletes use a lot of marijuana for good reason,” Hall told me. “I think you’d be surprised how many do it, at a high level. In snow sports, it’s kind of a given that you’ll see a lot of smokers out there; it’s been ingrained in the mountain culture for quite a while. People don’t look down on it as much. But I’ve talked to athletes in motocross, skateboarding, snowboarding, surfing, and BASE jumping who use chron. Lots of them. Just like the businessmen and politicians behind closed doors.”

Hall is careful, though, to say that it’s not for everyone. “I mean, some people just can’t use marijuana: it makes them go bananas. I don’t think those are the type that should be using it on a daily basis or on the mountain. But, for me, it’s just a good thing for my brain. I’ve got a pretty fast brain: it goes a million miles an hour, and the chron calms it down. When I smoke and put on a pair of skis, I know exactly what’s going to happen. I feel the flow, you know what I mean? But you can give it to somebody else who might not even be able to put on their skis.”